Dolby CP750 Digital Cinema Processor Manual - Projectionniste.net

® 

Dolby CP750 Digital 

Cinema Processor 

Manual 

Issue 4 Part Number 9110270

. 

Corporate Headquarters 

Dolby Laboratories, Inc. 

100 Potrero Avenue 

San Francisco, CA 94103‐4813 USA 

Telephone 415‐558‐0200 

Fax 415‐863‐1373 

www.dolby.com 

European Headquarters 


Wootton Bassett 

Wiltshire SN4 8QJ England 

Telephone 44‐1793‐842100 

Fax 44‐1793‐842101 


DISCLAIMER OF WARRANTIES: 

EQUIPMENT MANUFACTURED BY DOLBY LABORATORIES IS WARRANTED AGAINST DEFECTS 

IN MATERIALS AND WORKMANSHIP FOR A PERIOD OF ONE YEAR FROM THE DATE OF 

PURCHASE. THERE ARE NO OTHER EXPRESS OR IMPLIED WARRANTIES AND NO WARRANTY 

OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, OR OF NONINFRINGEMENT 

OF THIRD‐PARTY RIGHTS (INCLUDING, BUT NOT LIMITED TO, COPYRIGHT AND PATENT 

RIGHTS). 

LIMITATION OF LIABILITY: 

IT IS UNDERSTOOD AND AGREED THAT DOLBY LABORATORIES’ LIABILITY, WHETHER IN 

CONTRACT, IN TORT, UNDER ANY WARRANTY, IN NEGLIGENCE, OR OTHERWISE, SHALL NOT 

EXCEED THE COST OF REPAIR OR REPLACEMENT OF THE DEFECTIVE COMPONENTS OR 

ACCUSED INFRINGING DEVICES, AND UNDER NO CIRCUMSTANCES SHALL DOLBY 

LABORATORIES BE LIABLE FOR INCIDENTAL, SPECIAL, DIRECT, INDIRECT, OR 

CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, DAMAGE TO SOFTWARE OR 

RECORDED AUDIO OR VISUAL MATERIAL), COST OF DEFENSE, OR LOSS OF USE, REVENUE, OR 

PROFIT, EVEN IF DOLBY LABORATORIES OR ITS AGENTS HAVE BEEN ADVISED, ORALLY OR IN 

WRITING, OF THE POSSIBILITY OF SUCH DAMAGES. 

Dolby, Pro Logic, and the double‐D symbol are registered trademarks of Dolby Laboratories. Surround EX 

is a trademark of Dolby Laboratories. All other trademarks remain the property of their respective owners. 

© 2009 Dolby Laboratories. All rights reserved. 

Part Number 9110270 

Issue 4 

S09/20825/21444 

ii 

Dolby ® CP750 Digital Cinema Processor Manual

Regulatory Notices 

FCC 

NOTE: This equipment has been tested and found to comply with the limits for a Class A 

digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide 

reasonable protection against harmful interference when the equipment is operated in a 

commercial environment. This equipment generates, uses, and can radiate radio frequency 

energy and, if not installed and used in accordance with this instruction manual, may cause 

harmful interference to radio communications. Operation of this equipment in a residential 

area is likely to cause harmful interference in which case the user will be required to correct 

the interference at his own expense. 

Canada 

This Class A digital apparatus complies with Canadian ICES‐003. 

EU/EMC 

This unit complies with the EMC requirement of EN55103‐1 and EN55103‐2 when operated 

in an E2 environment in accordance with this manual. 

Important Safety Instructions 

1. Read these instructions. 

2. Keep these instructions. 

3. Heed all warnings. 

4. Follow all instructions. 

5. Do not use this apparatus near water. 

6. WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to 

rain or moisture. 

7. Clean only with dry cloth. 

8. Do not install near any heat sources such as radiators, heat registers, stoves, or other 

apparatus (including amplifiers) that produce heat. 

9. No naked flame sources, such as lighted candles, should be placed on the apparatus 

10. Protect the power cord from being walked on or pinched particularly at plugs, 

convenience receptacles, and the point where they exit from the apparatus. 

11. Only use attachments/accessories specified by the manufacturer. 

12. Unplug this apparatus when unused for long periods of time. 

13. Refer all servicing to qualified service personnel. Servicing is required when the 

apparatus has been damaged in any way, such as power‐supply cord or plug is 

damaged, liquid has been spilled or objects have fallen into the apparatus, the 

apparatus has been exposed to rain or moisture, does not operate normally, or has 

been dropped. 

14. Do not expose the apparatus to dripping or splashing and no objects filled with 

liquids, such as vases, shall be placed on the apparatus. 

Dolby ® CP750 Digital Cinema Processor Manual 

iii

15. CAUTION: Troubleshooting must be performed by a trained technician. To reduce the 

risk of electric shock, do not attempt to service this equipment unless you are 

qualified to do so. 

16. Do not defeat the safety purpose of the polarized or grounding‐type plug. A polarized 

plug has two blades with one wider than the other. A grounding‐type plug has two 

blades and a third grounding prong. The wide blade or the third prong is provided 

for your safety. If the provided plug does not fit into your outlet, consult an electrician 

for replacement of the obsolete outlet. 

17. This apparatus must be earthed (grounded) by connecting to a correctly wired and 

earthed power outlet. 

18. Ensure that your mains supply is in the correct range for the input power requirement 

of the unit. 

19. In order to reduce the risk of electrical shock, the power cord must be disconnected 

when the power supply assembly is removed. 

20. This equipment is designed to mount in a suitably ventilated 19” rack; ensure that any 

ventilation slots in the unit are not blocked or covered. 

21. The mains power disconnect device for this unit is the plug‐in mains cord rather than 

a power switch. The mains cord must remain readily accessible for disconnecting 

mains power. 

22. To avoid exposure to dangerous voltages and to avoid damage to the unit, do not 

connect the rear‐panel Ethernet port to telephone circuits. 

23. As the colors of the cores in the mains lead may not correspond with the colored 

markings identifying the terminals in your plug, proceed as follows: 

• The green and yellow core must be connected to the terminal in the plug 

identified by the letter E, or by the earth symbol , or colored green, or green 

and yellow. 

• The blue core must be connected to the terminal marked with the letter N or 

colored black. 

• The brown core must be connected to the terminal marked with the letter L or 

colored red. 

24. This apparatus must be earthed. 

Fuses 

WARNING: Check that the correct fuses have been installed. For continued protection 

against risk of fire, replace only with fuses of the same type and rating. 

WEEE 

PRODUCT END‐OF‐LIFE INFORMATION 

This product was designed and built by Dolby Laboratories to provide many years of 

service, and is backed by our commitment to provide high‐quality support. When it 

eventually reaches the end of its serviceable life, it should be disposed of in accordance 

with local or national legislation. 

For current information please visit our website at: http://www.dolby.com/environment 

iv 


IMPORTANT SAFETY NOTICE 

This unit complies with safety standard EN60065 as appropriate. The unit shall not be exposed to dripping or splashing and no objects filled with liquids, such as 

coffee cups, shall be placed on the equipment. To ensure safe operation and to guard against potential shock hazard or risk of fire, the following must be 

observed: 

o Ensure that your mains supply is in the correct range for the input power requirement of the unit. 

o Ensure fuses fitted are the correct rating and type as marked on the unit. 

o The unit must be earthed by connecting to a correctly wired and earthed power outlet. 

o The power cord supplied with this unit must be wired as follows: 

Live—Brown Neutral—Blue Earth—Green/Yellow 

GB 

IMPORTANT – NOTE DE SECURITE 

Ce materiel est conforme à la norme EN60065. Ne pas exposer cet appareil aux éclaboussures ou aux gouttes de liquide. Ne pas poser dʹobjets remplis de liquide, tels que des 

tasses de café, sur lʹappareil. Pour vous assurer dʹun fonctionnement sans danger et de prévenir tout choc électrique ou tout risque dʹincendie, veillez à observer 

les recommandations suivantes. 

F 

o Le selecteur de tension doit être placé sur la valeur correspondante à votre alimentation réseau. 

o Les fusibles doivent correspondre à la valeur indiquée sur le materiel. 

o Le materiel doit être correctement relié à la terre. 

o Le cordon secteur livré avec le materiel doit être cablé de la manière suivante: 

Phase—Brun Neutre—Bleu Terre—Vert/Jaune 

WICHTIGER SICHERHEITSHINWEIS 

Dieses Gerät entspricht der Sicherheitsnorm EN60065. Das Gerät darf nicht mit Flüssigkeiten (Spritzwasser usw.) in Berührung kommen; stellen Sie keine Gefäße, z.B. 

Kaffeetassen, auf das Gerät. Für das sichere Funktionieren des Gerätes und zur Unfallverhütung (elektrischer Schlag, Feuer) sind die folgenden Regeln unbedingt 

einzuhalten: 

o Der Spannungswähler muß auf Ihre Netzspannung eingestellt sein. 

D 

o Die Sicherungen müssen in Typ und Stromwert mit den Angaben auf dem Gerät übereinstimmen. 

o Die Erdung des Gerätes muß über eine geerdete Steckdose gewährleistet sein. 

o Das mitgelieferte Netzkabel muß wie folgt verdrahtet werden: 

Phase—braun Nulleiter—blau Erde—grün/gelb 

NORME DI SICUREZZA – IMPORTANTE 

Questa apparecchiatura è stata costruita in accordo alle norme di sicurezza EN60065. Il prodotto non deve essere sottoposto a schizzi, spruzzi e gocciolamenti, e nessun tipo di 

oggetto riempito con liquidi, come ad esempio tazze di caffè, deve essere appoggiato sul dispositivo. Per una perfetta sicurezza ed al fine di evitare eventuali rischi di scossa 

êlettrica o dʹincendio vanno osservate le seguenti misure di sicurezza: 

o Assicurarsi che il selettore di cambio tensione sia posizionato sul valore corretto. 

o Assicurarsi che la portata ed il tipo di fusibili siano quelli prescritti dalla casa costruttrice. 

I 

o Lʹapparecchiatura deve avere un collegamento di messa a terra ben eseguito; anche la connessione rete deve 

avere un collegamento a terra. 

o Il cavo di alimentazione a corredo dellʹapparecchiatura deve essere collegato come segue: 

Filo tensione—Marrone Neutro—Blu Massa—Verde/Giallo 

AVISO IMPORTANTE DE SEGURIDAD 

Esta unidad cumple con la norma de seguridad EN60065. La unidad no debe ser expuesta a goteos o salpicaduras y no deben colocarse sobre el equipo recipientes con liquidos, 

como tazas de cafe. Para asegurarse un funcionamiento seguro y prevenir cualquier posible peligro de descarga o riesgo de incendio, se han de observar las 

siguientes precauciones: 

o Asegúrese que el selector de tensión esté ajustado a la tensión correcta para su alimentación. 

E 

o Asegúrese que los fusibles colocados son del tipo y valor correctos, tal como se marca en la unidad. 

o La unidad debe ser puesta a tierra, conectándola a un conector de red correctamente cableado y puesto a tierra. 

o El cable de red suministrado con esta unidad, debe ser cableado como sigue: 

Vivo—Marrón Neutro—Azul Tierra—Verde/Amarillo 

VIKTIGA SÄKERHETSÅTGÄRDER! 

Denna enhet uppfyller säkerhetsstandard EN60065. Enheten får ej utsättas för yttre åverkan samt föremål innehållande vätska, såsom kaffemuggar, får ej placeras på 

utrustningen. För att garantera säkerheten och gardera mot eventuell elchock eller brandrisk, måste följande observeras: 

o Kontrollera att spänningsväljaren är inställd på korrekt nätspänning. 

o Konrollera att säkringarna är av rätt typ och för rätt strömstyrka så som anvisningarna på enheten föreskriver. 

S 

o Enheten måste vara jordad genom anslutning till ett korrekt kopplat och jordat el‐uttag. 

o El‐sladden som medföljer denna enhet måste kopplas enligt foljande: 

Fas—Brun Neutral—Blå Jord—Grön/Gul 

BELANGRIJK VEILIGHEIDS‐VOORSCHRIFT: 

Deze unit voldoet aan de EN60065 veiligheids‐standaards. Dit apparaat mag niet worden blootgesteld aan vocht. Vanwege het risico dat er druppels in het apparaat vallen, dient 

u er geen vloeistoffen in bekers op te plaatsen. Voor een veilig gebruik en om het gevaar van electrische schokken en het risico van brand te vermijden, dienen de 

volgende regels in acht te worden genomen: 

o Controleer of de spanningscaroussel op het juiste Voltage staat. 

NL 

o Gebruik alleen zekeringen van de aangegeven typen en waarden. 

o Aansluiting van de unit alleen aan een geaarde wandcontactdoos. 

o De netkabel die met de unit wordt geleverd, moet als volgt worden aangesloten: 

Fase—Bruin Nul—Blauw Aarde—Groen/Geel 


v

Figure ii‐1 

This symbol that appears on the unit rear panel is intended to alert the user 

to the presence of uninsulated “dangerous” voltage within the product’s 

enclosure that maybe of sufficient magnitude to constitute a risk of electric 

shock to persons. 

Figure ii‐2 

Figure ii‐3 

Figure ii‐4 

This symbol is intended to alert the user to the presence of important 

safety operating and maintenance instructions. 

Figure ii‐5 

vi 


Table of Contents 

Chapter 1 Introduction 

1.1 About This Manual..............................................................................................................2 

1.2 CP750 Front Panel .............................................................................................................2 

1.2.1 Front-Panel Menu Navigation Buttons .....................................................................2 

1.2.2 Front-Panel Status Display ......................................................................................3 

1.2.3 Mute Button..............................................................................................................4 

1.2.4 Main Fader Knob .....................................................................................................4 

1.2.5 USB Port ..................................................................................................................5 

1.2.6 Digital Input Selection Buttons .................................................................................5 

1.2.7 Valid Input LEDs ......................................................................................................5 

1.2.8 Analog Inputs...........................................................................................................6 

1.3 CP750 Rear Panel..............................................................................................................6 

1.3.1 AC Input ...................................................................................................................7 

1.3.2 Backup Power Port ..................................................................................................7 

1.3.3 Ethernet Port............................................................................................................7 

1.3.4 RS-232 Serial Port ...................................................................................................7 

1.3.5 Remote Connector...................................................................................................7 

1.3.6 4xAES IN Connector................................................................................................7 

1.3.7 Automation Connector .............................................................................................8 

1.3.8 1xAES IN Connectors ..............................................................................................8 

1.3.9 Opt In Connector......................................................................................................8 

1.3.10 NonSync Input Connector .......................................................................................8 

1.3.11 Aux Out Connectors ................................................................................................8 

1.3.12 H/I Out Connector....................................................................................................9 

1.3.13 Mic. Gain .................................................................................................................9 

1.3.14 Mic. Input .................................................................................................................9 

1.3.15 Main Audio Output Connector .................................................................................9 

1.3.16 Multi-Channel Analog Input Connector....................................................................9 

Chapter 2 Installation 

2.1 CP750 Floating Signal Grounds .......................................................................................11 

2.2 Digital Audio Inputs...........................................................................................................11 

2.2.1 Consumer Interface Standards for Digital Audio....................................................12 

2.2.2 Cable Issues ..........................................................................................................12 

2.2.3 Multiple Sources: Conversion Between Interface Standards.................................12 

2.3 Mounting the CP750.........................................................................................................13 

2.4 Connections......................................................................................................................13 

2.5 Fuse Information...............................................................................................................13 

2.6 Mains Power Wiring..........................................................................................................14 

2.7 Cable Diagram..................................................................................................................14 


vii

Chapter 3 Installing, Launching, and Connecting the Setup Software 

3.1 System Requirements ......................................................................................................17 

3.2 Installing the Software ......................................................................................................17 

3.3 Connecting the Hardware.................................................................................................18 

3.4 Launching the Setup Application ......................................................................................18 

3.5 Connecting to a Local or Remote Device .........................................................................18 

Chapter 4 Configuring the CP750 Software 

4.1 Using the Application Tabs to Configure a CP750 ...........................................................21 

4.1.1 Profile Tab..............................................................................................................21 

4.1.2 Network/Time Tab..................................................................................................22 

4.1.3 General Settings ....................................................................................................23 

4.1.4 Input Settings.........................................................................................................25 

4.1.5 Digital Input 1.........................................................................................................25 

4.1.6 Digital Inputs 2, 3, and 4 ........................................................................................27 

4.1.7 Analog Input...........................................................................................................28 

4.1.8 Nonsync Input ........................................................................................................29 

4.1.9 Mic Input ................................................................................................................30 

4.2 Saving Settings in a Configuration File.............................................................................31 

4.3 Loading a Saved Configuration File .................................................................................31 

4.4 Using Expert View ............................................................................................................31 

4.5 Updating the CP750 Firmware .........................................................................................32 

Chapter 5 Aligning the Auditorium 

5.1 Checking Theatre Equipment ...........................................................................................35 

5.1.1 Speakers................................................................................................................35 

5.1.2 Amplifiers ...............................................................................................................36 

5.1.3 Air Conditioning......................................................................................................36 

5.2 Microphone Placement.....................................................................................................36 

5.3 Initial Setup.......................................................................................................................37 

5.4 Calibrating the Internal SPL Meter ...................................................................................38 

5.5 Initial Output-Level Adjustment.........................................................................................39 

5.5.1 Setting Main Channel Levels .................................................................................39 

5.5.2 Subwoofer Levels ..................................................................................................40 

5.6 Room Equalization ...........................................................................................................41 

5.6.1 Setting Bulk EQ......................................................................................................42 

5.6.2 Using EQ Assist .....................................................................................................42 

5.6.3 Making Fine Adjustments to Individual Bands .......................................................42 

5.6.4 Adjusting LFE Channel EQ ....................................................................................43 

5.7 Final Output-Level Calibration ..........................................................................................43 

5.7.1 Main Channels .......................................................................................................43 

5.7.2 Subwoofer Channel Level......................................................................................44 

5.7.3 Subwoofer Speaker Polarity Check .......................................................................44 

5.8 Final Sound Check ...........................................................................................................44 

5.9 Nonsync Level Adjustment ...............................................................................................45 

5.9.1 Noise Floor Optimization........................................................................................45 

Chapter 6 Remote Control and Monitoring 

6.1 Status Monitoring and Level Control in the Setup Software .............................................47 

viii 


6.2 ASCII Control....................................................................................................................47 

6.2.1 Connections ...........................................................................................................47 

6.2.2 Standard and Full Control ......................................................................................48 

6.2.3 Command Syntax ..................................................................................................48 

6.2.4 Command Sets ......................................................................................................49 

6.3 SNMP ...............................................................................................................................58 

Chapter 7 Technical Reference 

7.1 CP750 Specifications .......................................................................................................61 

7.1.1 Audio Inputs ...........................................................................................................61 

7.1.2 Audio Outputs ........................................................................................................61 

7.1.3 Other Input/Output .................................................................................................62 

7.1.4 Audio Processing...................................................................................................63 

7.1.5 Other Parameters ..................................................................................................63 

7.1.6 Optional Accessories Ordered Separately.............................................................64 

7.1.7 Power Requirements .............................................................................................64 

7.1.8 Construction...........................................................................................................64 

7.1.9 Dimensions and Weight .........................................................................................64 

7.1.10 PC Connection ......................................................................................................64 

7.1.11 Input Selector Buttons ...........................................................................................64 

7.1.12 Indicators ...............................................................................................................64 

7.1.13 Environmental Conditions......................................................................................64 

7.1.14 Regulatory Notices ................................................................................................65 

7.2 Rear-Panel Connector Descriptions and Types ...............................................................65 

7.2.1 Backup Power Connector ......................................................................................65 

7.2.2 RS-232 Serial Port .................................................................................................66 

7.2.3 Remote Fader Connector ......................................................................................66 

7.2.4 4xAES IN Connector..............................................................................................67 

7.2.5 Automation Connector ...........................................................................................68 

7.2.6 Mic. Input Connector..............................................................................................68 

7.2.7 Main Audio Output and Multi-Channel Input Connectors.......................................69 

7.2.8 RS-232 ASCII String Commands...........................................................................70 

7.3 Remote Commands and Control ......................................................................................70 

7.3.1 Serial......................................................................................................................70 

7.3.2 Ethernet .................................................................................................................71 


ix

List of Figures 

Figure 1-1 CP750 Front Panel ................................................................................................................ 2 

Figure 1-2 Front-Panel Display ............................................................................................................... 4 

Figure 1-3 Fader Characteristic .............................................................................................................. 5 

Figure 1-4 CP750 Rear Panel................................................................................................................. 6 

Figure 2-1 Star Washers and Rack-Mounting Screws.......................................................................... 13 

Figure 2-2 CP750 Inputs and Outputs .................................................................................................. 15 

Figure 3-1 Installer Welcome Screen.................................................................................................... 17 

Figure 3-2 Action Menu......................................................................................................................... 18 

Figure 4-1 Profile Tab ........................................................................................................................... 21 

Figure 4-2 Network/Time Tab ............................................................................................................... 23 

Figure 4-3 General Settings Tab........................................................................................................... 24 

Figure 4-4 Digital Input 1 Tab ............................................................................................................... 25 

Figure 4-5 Digital Input 2 Tab ............................................................................................................... 28 

Figure 4-6 Analog Input Tab ................................................................................................................. 29 

Figure 4-7 Nonsync Input Tab .............................................................................................................. 30 

Figure 4-8 Mic Input Tab....................................................................................................................... 30 

Figure 4-9 Selecting Save in the File Menu .......................................................................................... 31 

Figure 4-10 Selecting Open in the File Menu ......................................................................................... 31 

Figure 4-11 Expert View Window............................................................................................................ 32 

Figure 4-12 Dolby Software Update Screen ........................................................................................... 33 

Figure 5-1 Microphone Placement for Equalization .............................................................................. 36 

Figure 5-2 Alignment Tab Showing Room Levels................................................................................. 38 

Figure 5-3 Channel Tune Tab Showing the Center Channel................................................................ 40 

Figure 5-4 Channel Tune Tab Showing LFE EQ .................................................................................. 41 

Figure 6-1 Virtual Status Monitor .......................................................................................................... 47 

Figure 7-1 Backup Power Connector Detail.......................................................................................... 65 

Figure 7-2 Cat. No. 868 Remote Fader Connector Detail..................................................................... 66 

Figure 7-3 Mic. Input Connector Detail ................................................................................................. 68 


xi

List of Tables 

Table 1-1 Digital Input Selection Button Functionality ............................................................................5 

Table 1-2 Analog Input Options ..............................................................................................................6 

Table 2-1 Examples of Available Balanced/Unbalanced Adapters.......................................................12 

Table 6-1 Normal Commands...............................................................................................................49 

Table 6-2 Full Control Commands........................................................................................................50 

Table 6-3 Supported MIB-2 MIBS.........................................................................................................58 

Table 6-4 Other Standard MIBs............................................................................................................59 

Table 6-5 V3 MIBS ...............................................................................................................................59 

Table 7-1 Rear-Panel Connector Descriptions and Types ...................................................................65 

Table 7-2 Backup Power Connector Pinout..........................................................................................66 

Table 7-3 Serial Port Pinout..................................................................................................................66 

Table 7-4 Remote Fader Connector Pinout..........................................................................................66 

Table 7-5 4xAES IN Connector Pinout .................................................................................................67 

Table 7-6 Automation Connector Pinout...............................................................................................68 

Table 7-7 Mic. Input Connector Pinout .................................................................................................69 

Table 7-8 Main Audio Output and Multi-Channel Audio Input Connector Pinout..................................69 

Table 7-9 ASCII String Commands ......................................................................................................70 


xiii

Chapter 1 

Introduction 

The Dolby ® CP750 Digital Cinema Processor is a direct result of Dolby Laboratories’ 

continued leadership in the development of innovative cinema technologies. The CP750 is 

a self‐contained, all‐digital cinema processor. It supports PCM and Dolby Digital audio, as 

well as Dolby Digital Surround EX TM , Dolby Pro Logic ® , and Dolby Pro Logic II playback. 

With the CP750, you can present high‐quality audio from the following audio sources and 

formats: 

• Dolby Digital Cinema system 

• Onscreen advertising servers 

• Digital VTRs 

• Digital satellite or cable TV receivers 

• DVDs 

• PCM 

• Dolby Digital consumer bitstreams 

The CP750 provides analog audio inputs for: 

• An external six‐ or eight‐channel processor 

• A nonsync source 

• A public address microphone 

Its analog audio outputs are balanced, with a multipin connector configured to the THX 

standard. Built‐in Ethernet, USB, and serial interfaces accommodate PC control and cinema 

network connectivity. 

An independently adjustable global audio delay is assigned to each input to ensure that 

sound and picture are perfectly synchronized during digital cinema presentations. 

Different delays can be assigned to different inputs, providing flexibility for alternative 

content sources, which often require different delays. 

The CP750 is compatible with existing theatre automation systems and ASCII command 

strings. Its ability to handle multiple formats and future upgrades make it an essential tool 

for an evolving digital cinema market. 

Installation is simplified by built‐in test instrumentation that includes a real‐time analyzer 

and signal generators for pink noise, sweep tones, tones, and a phase check thumper. 

Third‐octave equalization, plus bass and treble trim controls, are provided for all channels. 

A digital parametric equalizer is provided for the Subwoofer channel. 

Easily programmed internal software manages audio settings and configuration. The 

full‐featured software package facilitates the setup process. 

Dolby ® CP750 Digital Cinema Processor Manual 1

Introduction 

Calibration settings for one unit can be stored on a PC, and, if desired, transferred directly 

to another CP750, minimizing the need for additional calibration after repairs. As 

improvements to the CP750 digital control and processing software are developed, the 

latest revisions are transferable from a PC to the CP750. 

Options available for the CP750 include the Cat. No. 868 Remote Fader and Cat. No. 994 

External Power Supply. 

1.1 About This Manual 

This manual covers both installation and use of the CP750. 

Following this introductory chapter are six chapters that give details of various topics: 

• Chapter 2 Installation 

• Chapter 3 Installing, Launching, and Connecting the Setup Software 

• Chapter 4 Configuring the CP750 Software 

• Chapter 5 Aligning the Auditorium 

• Chapter 6 Remote Control and Monitoring 

• Chapter 7 Technical Reference 

1.2 CP750 Front Panel 

The CP750 front panel shown in Figure 1‐1 includes the following components from left to 

right: 

• Front‐panel menu navigation buttons 

• Status display 

• Mute button 

• Main fader knob 

• USB port for firmware upgrades and setup software 

• Seven buttons that select an input source: Digital 1, Digital 2, Digital 3, Digital 4, Multi-Ch 

Analog, NonSync, and Mic 

• Four LEDs that indicate the presence of a Valid signal on each digital input. Digital 1 

and Digital 4 have valid signals in Figure 1‐1. 

Figure 1‐1 

CP750 

Digital Cinema Processor 

Input Select 

Digital 1 Digital 2 Digital 3 Digital 4 

Multi-Ch 

Analog NonSync Mic. 

 

Valid 

Figure 1-1 

CP750 Front Panel 

1.2.1 Front-Panel Menu Navigation Buttons 

The menu control buttons to the left of the display, shown in Figure 1‐1, are used by both 

the operator and the service engineer to navigate front‐panel screen menus, select various 

menu options, and store setup data. 

2 Dolby ® CP750 Digital Cinema Processor Manual


The menu button is used to step through the menu list. Pressing and releasing the button 

once changes the display to the next menu item. Pressing and holding the button while 

rotating the main fader knob steps the display through all menu items. 

The check mark button is used to accept the settings displayed on the front‐panel screen 

and store it in CP750 memory. Changes to settings occur immediately, but are not 

immediately saved. 

The button blinks when there are unsaved parameter changes. 

Caution: Do not disconnect power to the unit while the checkmark button is blinking. 

1.2.2 Front-Panel Status Display 

Day‐to‐day operation of the CP750 is performed through interaction with the front‐panel 

status display shown in Figure 1‐2. 

Processing Display 

The top line displays the processing being applied to the audio. The supported processes 

are: 

• Dolby Pro Logic 

• Dolby Pro Logic II 

• Dolby Digital 

• Dolby Digital Surround EX 

• Discrete 

Volume Display 

The main fader level is displayed as a two‐digit number. As with previous generations of 

Dolby cinema processors, a fader setting of 7.0 (0 dB) is the nominal correct operating level. 

7.0 matches the level used during production of the motion picture. 

Input Display 

The bottom line of the display shows the type of audio being input. 

Meter Display 

The circle of lights surrounding the display text serves as channel meters when the CP750 

is in use. 


Introduction 

Figure 1‐2 

Left 

Center 

Right 

Processing 

Volume 

Input 

Subwoofer 

Left Surround 

Right Surround 

Figure 1-2 

Front-Panel Display 

1.2.3 Mute Button 

Pressing the mute button shown in red in Figure 1‐1 fades the audio output to all channels 

without disturbing the current main fader setting. Fade‐in and fade‐out speeds are 

separately adjustable from 0.2 to 5 seconds, using the PC setup software. The mute button 

flashes red when activated. 

1.2.4 Main Fader Knob 

Use this knob to adjust the sound level. A fader reading of 7.0 is the nominal correct 

operating level. The main fader knob rotates continuously with no end stops. The knob is 

also used to adjust parameters during setup operations. 

When the fader knob is rotated between readings of 0 and 4.0, the output level changes in 

20 dB steps between –90 and –10 dB. When the fader knob is rotated between readings 4.0 

and 10, the output level changes in 3.33 dB steps between –10 and –10 dB. Figure 1‐3 shows 

the characteristic graph. 



Figure 1‐3 

10 

0 

31/3db 

per step 

-10 

-20 

-30 

Output 

-40 

Level (dB) 

-50 

20 dB 

per step 

-60 

-70 

-80 

-90 

0 

1 

2 3 4 5 6 7 8 

9 

10 

Fader Level 

Figure 1-3 

Fader Characteristic 

1.2.5 USB Port 

The USB port is provided for connecting to a PC. You can use it either to set up the unit or 

to update the CP750 firmware. 

1.2.6 Digital Input Selection Buttons 

When you press any of the Digital 1, Digital 2, Digital 3, or Digital 4 push buttons, that button 

lights up, indicating that the selected input channel is active. Pressing one of these buttons 

selects a specific digital input source, as shown in Table 1‐1. The CP750 switches 

automatically between PCM and Dolby Digital bitstreams. 

Table 1-1 

Digital Input Selection Button Functionality 

Input Button 

Digital 1 




Input Source Selected 

Selects the input signal from the 4xAES DIGITAL 1 connector (four‐channel 

pairs, 25‐pin D‐connector) 

Selects the input signal from the 1xAES DIGITAL 2 connector (BNC) 

Selects the input signal from the 1xAES DIGITAL 3 connector (BNC) 

Selects the input signal from the 1xAES DIGITAL 4 connector (S/PDIF optical) 

1.2.7 Valid Input LEDs 

Each digital input push button has a green Valid LED located beneath it. These LEDs light 

up when the CP750 detects a valid signal on the respective input, whether or not the input 

is selected. Digital 1 and Digital 4 have valid signals in Figure 1‐1. 


Introduction 

1.2.8 Analog Inputs 

The CP750 has the three analog inputs, listed in Table 1‐2. 

Table 1-2 

Analog Input 

Multi-Ch Analog 

NonSync 

Mic. 

Analog Input Options 

Rear-Panel Input Source Selected 

Selects the input signal from the MULTI-CHANNEL ANALOG INPUT connector 

(eight channels, 25‐pin D‐connector) 

Selects the input signal from the NONSYNC INPUT L and R RCA jacks 

Selects the input signal from the MIC. INPUT 3‐prong XLR connector 

1.3 CP750 Rear Panel 

Figure 1‐4 

100–240 Vac ~ 50–60 Hz 30W 

U L 

C US 

LISTED 

PROFESSIONAL AUDIO 

EQUIPMENT 4J06 

CAUTION 

To reduce the risk of fire 

replace only with same 

type and rating 

250V time-lag fuse. 

FUSE T 3.15A L 

5mmx20mm 

25 

BACK-UP 

POWER 

Dolby, Pro Logic and the double-D symbol 

are registered trademarks of Dolby Laboratories. 



ETHERNET 

ACT 

LINK 

Risk of electric shock. 

Do not open. 

No user serviceable parts 

inside. Refer all service 

to qualified personnel. 

This equipment must be 

earthed/grounded. 

RS-232 

This device complies with Part 15 of the FCC Rules. 

Operation is subject to the following two conditions: (1) this 

device may not cause harmful interference, and (2) this 

device must accept any interference received, including 

interference that may cause undesired operation. 

This Class A digital apparatus complies with Canadian ICES003. 

REMOTE 

NOT ETHERNET 

4xAES IN 

DIGITAL 1 

AUTOMATION 

NONSYNC AUX 

INPUT OUT 

L 7 H/I 

1xAES IN 

OUT 

OPT IN 

MIC. 

R 8 

GAIN 

DIGITAL 2 DIGITAL 3 DIGITAL 4 

MIC. 

INPUT 

PUSH 

MAIN 

AUDIO OUTPUT 

MULTI-CHANNEL 

ANALOG INPUT 

Figure 1-4 

CP750 Rear Panel 

The CP750 rear panel, shown in Figure 1‐2, includes the following components: 

• AC input. 

• BACKUP POWER—4‐prong female XLR connector for use with the Cat. No. 994 

External Power Supply. 

• Ethernet—RJ‐45 port for remote control through ASCII command strings, Dolby 

Digital Cinema Theatre Management Software, unit setup, and firmware updates. See 

Section 7.2.8 for details on the command strings. 

Note: 

The CP750 supports 10Base‐T and 100Base‐T data rates. Gigabit 

Ethernet data rate is not supported. 

• RS-232—9‐pin female D‐connector for control via ASCII command strings. 9600 baud, 

no parity, 1 stop bit. See Section 7.2.8 for details on the command strings. See 

Section 7.2.2 for pinout details. 

• REMOTE—RJ‐45 port for communication with the Cat. No. 868 Remote Fader. See 

Section 7.2.3 for pinout details. This is not an Ethernet connection but can be 

connected with any standard Ethernet cable. 

• 4xAES IN—25‐pin female D‐connector labeled DIGITAL 1 carrying four digital channel 

pairs. See Section 7.2.4 for pinout details. 

• AUTOMATION—25‐pin female D‐connector for cinema automation control. See 

Section 7.2.5 for pinout details. 

• Two 1xAES IN—BNC connectors labeled DIGITAL 2 and DIGITAL 3. 

• OPT IN—Optical S/PDIF input connector labeled DIGITAL 4. 

• NONSYNC INPUT—2 RCA jacks labeled L and R that accept 3 V RMS 

maximum input. 

• AUX OUT—RCA jacks labeled 7 and 8 always carry channel pair 7/8 of the 4xAES 

input. If present, HI and VI‐N signals likely use this pair. 



• H/I OUT—RCA jack for hearing impaired output. This is a center‐weighted sum of 

L‐C‐R. 

• MIC. GAIN—For adjusting the gain of the microphone pre‐amp. 

• MIC. INPUT—3‐pin female XLR connector for a PA or auditorium equalization 

microphone. Phantom power can be applied using the setup software. 

• MAIN AUDIO OUTPUT—25‐pin female D‐connector balanced audio output to the 

auditorium sound system. See Section 7.2.7 for pinout details. 

• MULTI-CHANNEL ANALOG INPUT—25‐pin female D‐connector carrying eight balanced 

analog channels. See Section 7.2.7 for pinout details. 

1.3.1 AC Input 

This is a simple unswitched IEC power inlet module. 

1.3.2 Backup Power Port 

This is a 4‐pin female XLR connector for use with the Cat. No. 994 External Power Supply. 

1.3.3 Ethernet Port 

This is an illuminated RJ‐45 10/100BASE‐T Ethernet port with activity LEDs, which 

provides an interface to a Dolby Digital Cinema network and also ASCII string commands 

over TCP to port 61408. You can also use this port for setup software and firmware 

upgrades. 

1.3.4 RS-232 Serial Port 

You can use this port for serial control using ASCII string commands. 

The equipment connected to this port should have its serial port set to 9600 baud, no parity, 

1 stop bit. Use a pin‐to‐pin serial cable. 

The same control functions are available through the Ethernet port. 

1.3.5 Remote Connector 

This is not an Ethernet connection, but an Ethernet cable is used to connect to the Cat. No. 

868 Remote Fader. 

1.3.6 4xAES IN Connector 

This 25‐pin female D‐connector, linked to the Digital 1 button, receives four AES/EBU 

streams. The four AES input signals must be time aligned with each other. Typically, this 

input connects to a Dolby Digital cinema server. It accommodates PCM audio at 96, 48, and 

44.1 kHz, and 32 kHz (16, 20, and 24 bits) and Dolby Digital at all data rates and sample 

rates. The decoding of Dolby Digital is restricted to the first AES3 channel pair. This 

connector has a floating ground. 


Introduction 

1.3.7 Automation Connector 

This connector is used to select an audio input, to read back the currently‐selected input, 

and to remotely assert the mute command. The pinout is listed in Section 7.2.5. 

The automation subsystem is referenced to pin 12, Automation Return. This is the ground 

for these functions, and is connected to the ground of the CP750 only through a 1 k 

resistor. An isolated power supply is provided so that connection to automation systems 

can be made without introducing hum due to ground loops. 

Caution: The isolated power supply can only function properly if the Automation Return 

pin is within ± 5 Volts DC (or peak AC) of the CP750 chassis ground. 

The automation control system is designed to accept contact closure inputs. A closed 

contact asserts a command. The low side of the contact closing switch or relay should be 

connected to Automation Return. 

Warning: UNDER NO CIRCUMSTANCES should power from an external source be 

supplied to any pin in this connector! Connecting external power is likely to 

damage the CP750. 

1.3.8 1xAES IN Connectors 

These BNC connectors are linked to the Digital 2 and Digital 3 buttons. They accommodate 

PCM audio at 96, 48, and 44.1, and 32 kHz (16, 20, and 24 bits) and Dolby Digital at all data 

rates and sample rates. A BNC male to RCA female adapter can interface with most 

consumer gear. These connectors have floating grounds. 

1.3.9 Opt In Connector 

This optical connector is linked to the Digital 4 button. It accommodates PCM audio at 96, 

48, 44.1, and 32 kHz (16, 20, and 24 bits) and Dolby Digital at all data rates and sample rates. 

1.3.10 NonSync Input Connector 

2 RCA jacks labeled L and R that accept 3 V RMS 

maximum input. 

1.3.11 Aux Out Connectors 

These analog output represents channel pair 7/8 of the 4xAES input. 

For the top output labeled 7, the source is Channel 7 of the 4xAES input. No equalization 

or level control is applied. 

For the lower output labeled 8, the source is Channel #8 of the 4xAES input. No 

equalization or level control is applied. 



1.3.12 H/I Out Connector 

The hearing‐impaired output signal, on the female RCA connector labeled H/I Out, is 

unbalanced. It is a center‐weighted analog sum of the L, C, and R channels. 

1.3.13 Mic. Gain 

This multi‐turn trimpot adjusts the gain of the mic preamp. If you use the microphone 

input for public address purposes, adjust this control for the desired volume in the 

auditorium. If you use it only for cinema alignment purposes, the trimpot will be adjusted 

using the setup software. 

1.3.14 Mic. Input 

This input is for use with a balanced output microphone. Phantom power is provided, and 

can be turned on and off under software control using the setup software. 

1.3.15 Main Audio Output Connector 

This connector is an eight‐channel analog output (L, C, R, Ls, Rs, SW, Bsl, and Bsr), which 

is present on a male 25‐pin D‐connector (300 mV reference level). 

Bsl and Bsr channels are required for Dolby Digital Surround EX installations. For other 

installations these channel can be configured to represent channel pair 7/8 of the 4xAES 

input. These mutually exclusive options are configured in the setup software. 

1.3.16 Multi-Channel Analog Input Connector 

This connector is an eight‐channel analog input (L, C, R, Ls, Rs, SW, Bsl, Bsr) designed to 

receive 300 mV RMS 

(ref) inputs from external sources and inputs on a female 25‐pin 

D‐connector. These inputs are balanced and floating, but the common mode voltage must 

not exceed ± 6V peak. 

Send Us Your Feedback About This Section 

If you have a question or comment about this chapter, send us an email. 


Chapter 2 

Installation 

2.1 CP750 Floating Signal Grounds 

The CP750 is designed to eliminate ground loops, which can occur when the unit is 

connected to multiple external equipment grounds. For this reason, the following CP750 

connectors have isolated grounds: 

• MAIN AUDIO OUTPUT and MULTI-CHANNEL ANALOG INPUT—Eight‐channel input and 

output are balanced and floating. Note that a common mode signal between the 

CP750 audio outputs and its chassis ground must not exceed +6 V peak. 

• AUTOMATION connector—The common is floating and can be +5 V peak from the 

chassis ground. 

• 1xAES IN BNC digital inputs—These are transformer isolated and their grounds can 

be +10 V peak from the chassis ground. 

• 4xAES D‐connector digital inputs—These are transformer isolated and their grounds 

can be +10 V peak from the chassis ground. 

Note: 

The RS‐232 input ground is connected to the CP750 chassis ground and is not 

floating. 

2.2 Digital Audio Inputs 

There are two professional interface standards for digital audio transmission: AES/EBU 

(also known as AES3) and AES‐3id. These methods stream the same digital data and 

professional audio header information over copper conductor links, but use different types 

of conductors and connectors. 

AES/EBU uses a balanced connection (two conductors plus shield) with a characteristic 

input impedance of 110, a nominal peak‐to‐peak signal level of 5 V, and, most commonly, 

XLR connectors. The typical maximum transmission distance is 100 meters (328 feet). 

AES‐3id uses an unbalanced connection (one signal conductor plus shield) with a 

characteristic input impedance of 75, peak‐to‐peak signal level of 1 V, and BNC (“push 

and twist”) connectors. The typical maximum transmission distance is 1,000 meters (3,280 

feet). 

Professional digital audio equipment typically uses the AES/EBU method because 

balanced operation yields superior noise immunity, as it does with analog audio signals, 

and because XLR connectors are the standard on analog professional audio equipment. 

Professional video equipment typically uses the AES‐3id interface, with BNC connectors. 

As with XLR connectors on professional audio equipment, the adoption of BNC 

connectors for the audio on professional video equipment stems from their use for the 

video signal. Also, the unbalanced AES‐3id signal can connect to more than one piece of 


Installation 

equipment by using the loop‐through connectors available on some devices. The signal is 

robust for long cable runs. 

2.2.1 Consumer Interface Standards for Digital Audio 

The consumer interface standard for digital audio transmission is S/PDIF (IEC 61937). 

S/PDIF uses coaxial unbalanced connections (one signal conductor plus shield) with a 

characteristic input impedance of 75 with RCA (phono) connectors, or a fiber‐optic cable 

link. The unbalanced coaxial connection has a peak‐to‐peak signal level of 0.5 V. The 

typical maximum transmission distance is 10 meters (33 feet). Although S/PDIF‐specific 

cables with suitable connectors can be purchased, you can also obtain good results using 

high‐quality 75 video cable with the appropriate connectors and/or adapters. 

2.2.2 Cable Issues 

Even in digital audio, noise‐free signals are very important. The cable used for digital 

signals is specifically designed for such use, although it looks the same as the cable used 

for analog audio or video signals. Any professional audio equipment or broadcast supply 

company can provide 110 cable with connectors (or without, if you’d like to terminate 

them yourself) for AES/EBU connections, and high‐quality 75 video cables with BNC 

connectors for AES‐3id connections. Use of cables or connectors not designed for digital 

transmission or with incorrect impedance compromises the integrity of the bitstream. This 

can result in unreliable hardware interconnections, especially with long cable runs. 

2.2.3 Multiple Sources: Conversion Between Interface Standards 

Although some details of the bitstreams used in the AES and S/PDIF standards are 

different, the audio information is exactly the same. As a result, most audio equipment 

accepts either standard with no need to convert the bitstream itself; this is the case with the 

CP750. However, if you intend to connect sources across different types of digital audio 

inputs, do not attempt to convert a digital interface type by directly wiring an XLR 

connector to a BNC or RCA plug. This causes an impedance mismatch and signal 

reflections, resulting in digital waveform degradation. This may appear to work, but the 

results are unreliable and dropouts occur. 

For conversion between the AES‐3id and S/PDIF formats, you can use high‐quality 

RCA‐to‐BNC adapters because the cable and impedance are both the same (75). 

For conversion between the AES/EBU and AES‐3id or AES/EBU and S/PDIF formats, a 

simple and economical method uses inline transformers. These devices perform the 

necessary impedance and balanced/unbalanced conversion. Table 2‐1 shows some 

examples of suitable adapters. The unbalanced connector in these examples is BNC. 

You can add BNC‐to‐RCA adapters for connecting to consumer S/PDIF connections. The 

following units use passive circuitry. 

Table 2-1 

Examples of Available Balanced/Unbalanced Adapters 

Adapter Type Neutrik ® Canare ® 

XLR female 110 in NA‐BF BCJ‐XJ‐TRA 

to BNC female 75 out 

BNC female 75 in 

to male XLR 110 out 

NA‐BM BCJ‐XP‐TRA 


Mounting the CP750 

Higher‐priced units incorporating active circuitry are also available. These offer additional 

features such as multiple inputs, inputs for optical connections, and multiple outputs. 

2.3 Mounting the CP750 

To avoid heat or hum pickup problems, do not mount the CP750 immediately above or 

below power amplifiers. Locate power amplifiers away from the CP750 to avoid hum 

pickup problems. Always leave a 1‐U space (43 mm, or 1.75 in) above and below the CP750 

to provide adequate ventilation. Install an air guide or baffle to deflect hot any air coming 

from equipment below the CP750. 

To ensure good ground contact, install a star washer on at least one (and preferably all) 

rack‐mounting screws as shown in Figure 2‐1. This will also aid in the prevention of 

electrical noise problems. 

Figure 2‐1 

Figure 2-1 

Star Washers and Rack-Mounting Screws 

Proper shielding and termination of cables and cable assemblies are also very important. 

Follow the methods shown in the wiring diagrams. 

2.4 Connections 

To connect the CP750 to your auditorium equipment, refer to Figure 2‐2 . 

For proper operation in locations where there is considerable interference, strictly adhere 

to the cable types, lengths, and pin assignments. Shields must connect only to the chassis 

and should not be paralleled with the negative side of inputs or outputs. 

Connector pinouts are listed in Section 7.2. 

2.5 Fuse Information 

The CP750 uses a universal‐switching power supply that handles the full range of nominal 

mains voltages between 100 and 240 VAC, and any frequency between 50 and 60 Hz. If a 

power supply fuse blows, do not attempt to replace it. Instead, contact Dolby Laboratories. 


Installation 

2.6 Mains Power Wiring 

In some countries, the primary mains cable may not have a connector fitted. 

Nonterminated leads must be properly wired to an approved mains connector in 

accordance with the following international code: 

• Brown wire: live or hot 

• Blue wire: neutral 

• Green wire: mains ground 

Warning: If you are uncertain about the wiring of your AC mains outlet, do not use it. 

Consult a qualified electrician. 

2.7 Cable Diagram 

The cable diagram for the CP750 rear panel is on page 15. 




Installation 

Cable Diagram 

Figure 2‐2 

Hearing 

Impaired 

System 

black 

red 

Digital Inputs: 

PCM 

Dolby Digital ( AC-3) 

4X AES Source 

Eight-channel PCM 

from Server 

Unbalanced Input amplifier 

one channel shown, applicable to all 

{ 

PA Microphone Input 

(Or Mic-multiplexer for setup) 

L+C+R 

Surround Speakers 

Screen Speakers 

Surround EX 

Speakers 

{ 

{ 

{ 

BSR 

BSL 

Red: 8 

Red: 19 

Black: 6 

Red: 16 

Black: 3 

Notes: 

1. Follow all local electrical and building codes. 

2. Use earthed (grounded) conduit wherever 

possible. Avoid routing signal wiring near electric 

motors, rectifiers, power wiring, dimmer wiring, or 

other sources of electrical noise. 

3. For two-conductor with shield wiring, use 

Belden 8451 two-conductor shielded cable or 

equivalent: tinned copper, twisted pair, 22 AWG 

stranded tinned copper drain wire, aluminumpolyester 

shield, 100 percent shield coverage, 

conductor to conductor (111 pF per meter). 

4. All shields must be connected to the chassis of 

the CP750 or DSP100/DSS200 rather than to 

circuit (audio) ground. This achieves the RF 

interference immunity required by European EMC 

standards. For D-connectors, a metal housing 

must be used and the shields must be connected 

100–240 Vac ~ 50–60 Hz 30W 

C UL US 

LISTED 

PROFESSIONAL AUDIO 

EQUIPMENT 4J06 

CAUTION 

To reduce the risk of fire 

replace only with same 

type and rating 

250V time-lag fuse. 

FUSE T 3.15A L 

5 mm x 20 mm 

25 

Dolby, Pro Logic and the double-D symbol 

are registered trademarks of Dolby Laboratories. 



Risk of electric shock. 

Do not open. 

No user serviceable parts 

BACK-UP 

inside. Refer all service 

to qualified personnel. 

POWER 

This equipment must be 

earthed/grounded. 

ETHERNET 

RS-232 

ACT LINK 

This device complies with Part 15 of the FCC Rules. 

Operation is subject to the following two conditions: (1) this 

device may not cause harmful interference, and (2) this 

device must accept any interference received, including 

interference that may cause undesired operation. 

This Class A digital apparatus complies with Canadian ICES003. 

REMOTE 

NOT ETHERNET 

4xAES IN 

DIGITAL 1 

AUTOMATION 

NONSYNC AUX 

INPUT OUT 

L 7 H/I 

1xAES IN 

OUT 

OPT IN 

MIC. 

R 8 

GAIN 

DIGITAL 2 DIGITAL 3 DIGITAL 4 

MIC. 

INPUT 

PUSH 

MAIN 

AUDIO OUTPUT 

MULTI-CHANNEL 

ANALOG INPUT 

F9110270_1A.CDR 

Cat. No. 994 

Back-up Power Supply 

( Optional) 

Auditorium Network 

Cat. No. 868 Remote Fader 

(Optional) 

Automation 

Input 

{ 

Mic. 

NonSync 

H/I 

Multi-Ch Analog 





CD or DVD Player 

Non-sync 

Source 

RS 

LS 

16 BSL 

19 BSR 

OUT channel 7 (if present) 

{ 

Eight-channel Analog Input 

(all unlabeled pins are chassis ground) 

normal operating level = 300 mV 


INSTALLATION WIRING 

Figure 2-2 

CP750 Inputs and Outputs 

Figure 2‐3 


Chapter 3 

Installing, Launching, and Connecting 

the Setup Software 

The CP750 is designed and built to be set up and administered remotely by software. Once 

installed and configured, the CP750 remote application gives you access to all of the unit’s 

functions. 

Begin by installing the software on a PC, which you can connect to the CP750 with a USB 

cable. 

3.1 System Requirements 

The CP750 setup software runs on Microsoft ® Windows ® XP and Windows Vista. 

3.2 Installing the Software 

To install the CP750 setup application, follow these steps: 

1. Open the CP750 Setup folder and run CP750Setup_x_x_x.exe. This file is named with 

the current software version number. 

The installer opens displaying the screen shown in Figure 3‐1. 

Figure 3‐1 

Figure 3-1 

Installer Welcome Screen 

2. Select the desired language. 

3. Follow the screen prompts until the installation is complete. 


Installing, Launching, and Connecting the Setup Software 

3.3 Connecting the Hardware 

There are three ways to connect computer hardware to the CP750. 

• The USB port on the front panel of the unit, shown in Figure 1‐1, is expressly designed 

for easy connection to laptop computers with a standard A to B cable. 

• You can connect a pin‐to‐pin serial cable to the RS-232 connector on the unit rear 

panel. 

• You can connect directly to the Ethernet connector on the unit rear panel. If your 

laptop supports Gigabit Ethernet, use a standard Ethernet cable. Otherwise, use a 

crossover cable. 

3.4 Launching the Setup Application 

To launch the CP750 setup application, click the Start button and scroll to Programs. In the 

Dolby folder, double‐click Dolby CP750 Setup. 

The Dolby ® CP750 setup window appears, as shown in Figure 4‐1. 

3.5 Connecting to a Local or Remote Device 

You can use the setup software Action menu, shown in Figure 3‐2, to connect to a local or a 

remote device. 

Figure 3‐2 

Figure 3-2 

Action Menu 

These options allow you to connect to a CP750 that is either connected to your PC (local 

device) or connected to an Ethernet network (remote device). If you select Connect to 

remote device, the system prompts you to enter an IP address. 

You must change your laptop’s TCP/IP properties to communicate properly with the CP750 

when connecting the setup software to a CP750 using a PC Ethernet connection. We 

recommend the following TCP/IP settings to enable your PC to communicate with a CP750 

using its default setting. 

IP address: 192.168.1.200 

Subnet mask: 255.255.255.128 

Default gateway: 192.168.1.129 

Note: The CP750 default IP address (for connecting) is 192.168.1.136. 


Connecting to a Local or Remote Device 




Chapter 4 

Configuring the CP750 Software 

4.1 Using the Application Tabs to Configure a CP750 

Each setup application tab controls a different part of the application’s function. They are 

discussed separately in the following sections. 

• Profile Tab—Lets you enter identifying information that is important for service calls 

and technical support 

• Network/Time Tab—Lets you specify unit addresses and connections 

• General Settings—Lets you define a power‐on mode, a subwoofer filter frequency, 

and a surround delay for the CP750. 

• Input Settings—Lets you define attributes and processing for each input 

• Alignment—Lets you optimize the sound in the auditorium. This important topic is 

described in detail in Chapter 5. 

4.1.1 Profile Tab 

When you launch and connect the CP750 setup software, the application opens with the 

Profile tab active, as shown in Figure 4‐1. 

Figure 4‐1 

Figure 4-1 

Profile Tab 

Here you enter identifying information about the auditorium equipment. This system 

information is particularly important if a service call is ever necessary. The key items are: 

• CP750 Serial Number—Read the number from the back of the CP750 unit. 



• Theatre Name–This must match the name registered in your Theatre Management 

Software (TMS). 

• Auditorium Number–This must match the number assigned to the Show Player. 

• Cinema Processor—Enter a name for your CP750. 

• Digital Cinema System—Identifying numbers for your cinema processing 

equipment. 

• Digital Cinema Projector—Identifying information for your projector. 

• Input Descriptions—The identifying text you enter here is repeated as the titles of the 

Input Settings tab. 

Tip: 

Assigning clear names to the digital inputs is an easy way to prevent input selection 

errors. 

The Profile tab displays the current network settings, but you can modify them only on the 

Network/Time tab. 

4.1.2 Network/Time Tab 

The Network/Time tab, shown in Figure 4‐2, lets you configure the CP750 Ethernet 

settings and time and date settings. 

The host name and IP address are echoed, read‐only, on the Profile tab. Network 

configuration and status are also available though the ASCII control interface. 

Ethernet Settings 

By default DHCP is turned off, and entries follow the Dolby ® Digital Cinema private 

network address naming convention in which the third octet indicates the auditorium 

number: 

• Host Name: CP750xxxxx 

• IP Address: 192.168.x.136 

• Subnet Mask: 255.255.255.128 

• Default Gateway: 192.168.x.129 

If you are using the Dolby TMS you need only enter the auditorium number in the third 

triad of the IP Address and Default Gateway fields. 

DHCP 

As soon as you click Enable, the IP Address, Subnet Mask, and Default Gateway change 

to 0.0.0.0 while the unit searches for a server and acquires valid addresses. This search and 

acquisition process may take up to 30 seconds. 

If no server is found, the displays stay at 0.0.0.0 past 30 seconds. 


Using the Application Tabs to Configure a CP750 

Figure 4‐2 

Figure 4-2 

Network/Time Tab 

If you make any changes, the system highlights two action buttons. Click one to either 

Discard Changes or Apply Changes. 

Time and Date 

You can change the time manually by dialing with the arrows in the Apply Time field. 

You can also load the local time from a server by clicking the Load Local Time button. 

You must click Apply to make changes to the unit’s stored date and time. 

4.1.3 General Settings 

This tab, shown in Figure 4‐3, lets you set four system attributes: 

• Power‐on Mode 

• Surround Delay 

• Main Audio Output Configuration 

• Mute Duration 



Figure 4‐3 

Figure 4-3 

General Settings Tab 

Power-on Mode 

The Power‐on Mode selects the input that is activated when the CP750 unit is powered on. 

You can select Last Setting, or any of the inputs. 

Surround Delay 

The setup application can calculate and set the General surround delay value based on 

theatre measurements entered here. Measurements may be entered in feet or meters. 

1. Click Feet or Meters to choose a unit of measure. 

2. Enter a Distance from screen to rear wall of theatre value between 0 and 200. 

3. Enter an Average distance between left and right Surround channels value between 

0 and 140. 

4. Click Calculate. 

The General value is adjustable from 0 to 150 ms in 1 ms steps. The display shows a marker 

every 10 ms. 

After you set the general surround delay for digital material, set the Pro Logic/Pro Logic II 

value which is applied to analog material. The minimum value for this slider is 20 ms 

because this value should always be 20 ms higher than the General value. 

Main Audio Output Configuration 

You can indicate that your auditorium is set up to use Dolby Digital Surround EX . 



Mute Duration 

The Fade In and Fade Out slider each have a range of 0.2 to 5.0 seconds in 0.1 second steps. 

Set a value either by moving the slider. 

4.1.4 Input Settings 

The Input Settings tab of the set up application consists of a separate tab for each input 

described separately in the sections that follow. 

4.1.5 Digital Input 1 

Figure 4‐4 shows the Digital Input 1 tab. The tab title is repeated from the Digital 1 input 

description on the Profile tab. 

Figure 4‐4 

Figure 4-4 

Digital Input 1 Tab 

On the Digital Input 1 tab you can configure: 

• Global Audio Delay 

• Mute Main Bsl/Bsr Output Pins 

• Fader Preset 

• PCM Channel Assignment 

• PCM Decode Mode 

• PCM Processing Mode 

• Dolby Digital Decode Mode 

• Dolby Digital Dialogue Normalization 



Global Audio Delay 

The Global Audio Delay field specifies an audio delay in addition to the CP750 decoding 

delay of approximately 7 ms for 4xAES PCM. Use this function to synchronize the audio 

with the video from digital cinema projectors, which add a video processing delay. Use the 

up and down arrows to set the Global Audio Delay between 0 and 250 ms. This delay 

value is set independently for each digital input. 

Note: 

Systems that use an external video scaler may add another decoding delay. 

Mute Main Bsl/Bsr Output Pins 

Choose Enable to mute these pins if your auditorium does not use them. 

Fader Preset 

To use the Fader Preset feature, choose Enable and indicate a value on the slider. This 

ensures that inputs play at correct values each time they are selected. 

PCM Channel Assignment 

The analog audio output channels (L, R, C, LFE, Ls, Rs) are always fixed and hardwired to 

a cinema processor. However, when a PCM bitstream’s input‐channel mapping is not a 

default SMPTE configuration (L/R, C/LFE, Ls/Rs), you must reassign the input channels to 

match the hardwired audio outputs. For channel reassignment, the surround delay and the 

LFE filter are always tied at the output, and therefore cause no problem. 

To reassign the input channels, use the drop‐down Assigned To menu for each of the AES 

Input channels or click one of the three preset buttons (L/R C/Sw Ls/Rs; L/C R/Ls Rs/Sw; 

or L/Ls C/Rs R/Sw). To activate your changes, click the Apply changes button. To cancel 

your changes, click the Discard changes button. 

PCM Decode Mode 

You can select one of four surround channel processing options: 

• None 

• Pro Logic 

• Pro Logic II 

• Surround EX 

PCM Processing Mode 

You have three choices of mode: 

• Minimum Latency—When selected, this default mode provides the quickest audio 

processing (approximately 7 ms) for PCM audio. 

• Silent Switch—When selected, the CP750 constantly checks for transitions between 

PCM and coded audio, and switches between the two silently. This mode adds a 40 

ms latency to the audio processing (for a total latency of approximately 47 ms). 



• Mute—When selected, PCM audio is muted. Dolby Digital plays normally. 

Note: 

Both Minimum Latency and Silent Switch automatically switch between PCM 

and coded audio. Minimum Latency may produce an audible snat during the 

transition. 

Dolby Digital Decode Mode 

You choose how the system decodes a two‐channel input stream. There are four options: 

• Auto 

• Pro Logic 


• Surround EX 

Auto decode mode follows the surround metadata parameter embedded in the coded 

bitstream. There is no metadata in PCM audio. If you choose Pro Logic or Pro Logic II 

decoding, your choice overrides the presence or absence of surround metadata in 

two‐channel coded bitstreams. 

Dolby Digital Dialogue Normalization 

When enabled, this option sets the decoder level shift according to the metadata embedded 

in the Dolby Digital bitstream. The default is Disable. 

4.1.6 Digital Inputs 2, 3, and 4 

The options available on these three tabs are identical. Figure 4‐5 shows the Digital Input 

2 tab. The tab titles are repeated from the input descriptions on the Profile tab. 



Figure 4‐5 

Figure 4-5 

Digital Input 2 Tab 

For these inputs you can configure: 




• PCM Processing Mode 

• Dolby Digital Decode Mode 

• Dolby Digital Dialogue Normalization 

The options for Global Audio Delay, Fader Preset, PCM Processing Mode, Dolby Digital 

Decode Mode, and Dolby Digital dialogue normalization and are identical to those on 

the Digital Input 1 tab. 

PCM Decode Mode 

There are three decoding options for two‐channel PCM streams: 

• None 

• Pro Logic 


4.1.7 Analog Input 

Figure 4‐6 shows the Analog Input tab. 



Figure 4‐6 

Figure 4-6 

Analog Input Tab 

On this tab you can set: 


• Mute Main Bsl/Bsr Output Pins 


• PCM Channel Assignment 


These choices operate identically to those on the Digital Input 1 tab. 

4.1.8 Nonsync Input 

On the Nonsync Input tab, shown in Figure 4‐7, you can choose: 



The options operate identically to those on other tabs. 

You can choose any of six supported formats for PCM: 

• Format 60 Nonsync 

• Format 70 Mono CS 

• Format 71 Mono C 

• Format 73 Pro Logic LCR 

• Format 74 Pro Logic with no subwoofer 

• Format 75 Pro Logic with a subwoofer 

You can also set an Input Trim using the slider. 



Figure 4‐7 

Figure 4-7 

Nonsync Input Tab 

4.1.9 Mic Input 

On the Mic Input tab, shown in Figure 4‐8, you can choose: 



The options operate identically to those on other tabs. 

The PCM Channel Assignment field allows you to assign the microphone input either the 

Center channel or the Surrounds. 

In the Phantom Power field, you can enable phantom power to the microphone as needed. 

Figure 4‐8 

Figure 4-8 

Mic Input Tab 


Saving Settings in a Configuration File 

4.2 Saving Settings in a Configuration File 

When you have completed configuration work on the CP750, you can save your settings to 

a .dlb parameter file. We recommend saving configuration files for use in the event your 

unit ever needs to be replaced. 

Caution: Take care to identify the settings file clearly, and store it separately from software 

update files, which also use the .dlb extension. 

Chose Save in the File menu as shown in Figure 4‐9, browse to the location on your PC 

where you want to save the file, enter a file name, and click Save. 

Figure 4‐9 

Figure 4-9 

Selecting Save in the File Menu 

To modify an existing .dlb file and save it under a different name, open the file, then select 

Save As in the File menu. 

4.3 Loading a Saved Configuration File 

A CP750 can be restored from an existing .dlb configuration file. 

To do so, choose Open in the File menu of the setup application, browse to the desired .dlb 

file on your PC, and open it. 

Figure 4‐10 

Figure 4-10 Selecting Open in the File Menu 

4.4 Using Expert View 

When you choose Expert View on the Window menu, all the CP750 parameters and 

command strings are available as shown in Figure 4‐11.You can modify a parameter 

highlighted in green by double clicking it and typing a new value. To return to the tab 

display, reselect Expert View. 



Figure 4‐11 

Figure 4-11 Expert View Window 

4.5 Updating the CP750 Firmware 

When you choose Update Software on the Action menu, the setup software closes and 

Dolby Software Update automatically opens and connects. You can then update the CP750 

firmware by following these directions. When the update is completed, Dolby Software 

Update closes and the setup software opens and reconnects. 

To update the CP750 firmware: 

1. Obtain the latest version of the CP750 setup application from Dolby Laboratories and 

install it on your PC. 

2. Obtain the .dlb update file from Dolby Laboratories and copy it to your PC. 

3. Connect your PC to the USB port on the CP750 front panel. 

4. Click Update Software on the Action menu to begin the update process. 

The Dolby Software Update window, shown in Figure 4‐12, opens. 


Updating the CP750 Firmware 

Figure 4‐12 

Figure 4-12 Dolby Software Update Screen 

5. Click Browse to find the .dlb update file on your PC, then click Open. 

6. Click Update. 

After a few seconds, a progress bar displays the status of the update process. When the 

process is completed, the CP750 automatically reboots with the updated firmware. 

You must close the Dolby Software Update window manually. 




Chapter 5 

Aligning the Auditorium 

The CP750 allows you to quickly and easily optimize the sound quality in the auditorium. 

The alignment process is discussed in the following sections: 

• Checking Theatre Equipment 

• Microphone Placement 

• Initial Setup 

• Calibrating the Internal SPL Meter 

• Initial Output‐Level Adjustment 

• Room Equalization 

• Final Output‐Level Calibration 

• Final Sound Check 

• Nonsync Level Adjustment 

5.1 Checking Theatre Equipment 

Thoroughly check the loudspeakers and power amplifiers for any sources of poor 

performance, using the checklists below as a guide. 

5.1.1 Speakers 

• Check loudspeaker cable condition and confirm that the cables are the correct gauge 

for the impedance of the speakers and the length of the run. 

• Check that the speakers are connected to the correct power amp channel. 

• Check for leaks in the low‐frequency driver cabinet which may sound like rattles. 

• Check for loose bolts or other hardware. 

• Check the speakers with an ohmmeter. If one channel requires markedly more 

equalization than the other, or if one speaker overloads at lower levels than the other 

speakers, an open driver circuit could be the cause. In systems with pairs of drivers, 

one voice coil of the pair may be open but the system will still function. 

• Check for missing drivers or other components. 

• Verify that crossover settings matching the type of drivers in use and the acoustics of 

the theatre. The high‐frequency driver level control must be set for the best possible 

frequency response before you attempt any equalization. This is especially true if the 

system uses active crossovers with biamp equipment. 

• Check for proper polarity between the low‐ and high‐frequency drivers, and between 

the channels. 

• Ensure that the speakers are correctly aimed into the auditorium, and that they are 

not obstructed by the screen frame, struts, or other objects. 



5.1.2 Amplifiers 

• Check for distortion. 

• Check for gross gain differences among amplifiers. If one amplifier differs in 

performance from the others, it should be checked and repaired. 

• Check for blown fuses. 

• Ensure that there is good air movement through power amplifiers. 

• Check any air filters. 

5.1.3 Air Conditioning 

If air‐conditioning noise is audible in the theatre, arrange for lubrication of the motor and 

fan bearings, adjustment of belts and drives, and cleaning of filters to minimize ambient 

noise. 

5.2 Microphone Placement 

Position a microphone multiplexer in the center of the auditorium listening area. Place each 

microphone in the reverberant field rather than in an area that receives the most direct 

energy from the speakers. In addition, avoid perfect symmetry. Arrange the microphones 

so that they do not form a square or rectangle parallel to the sides of the room. Take care 

not to place any of the multiplexing microphones on the auditorium center line. Standing 

waves and nodes can cause measurement errors. 

During final SPL calibration, microphone number 1 should be placed two‐thirds of the 

distance from the front speakers to the rear, at the exact side‐to‐side center of the room, 

approximately five feet above the floor level, and rotated 45 degrees upward toward the 

screen. (Some multiplexer microphones are designed to be pointed directly at the ceiling.) 

Placement of this microphone is important for output level adjustments. 

Figure 5‐1 

Figure 5-1 

Microphone Placement for Equalization 

If a single microphone is used, which we do not recommend, use the number 1 position 

detailed above, but place it slightly off center during equalization. 

Route the output cable to the CP750 and connect it to the Mic. Input connector on the CP750 

rear panel. 

Note: 

Many microphones require phantom power, which can be enabled in the CP750 

setup software. 


Initial Setup 

5.3 Initial Setup 

Prepare for the alignment process with the following steps: 

1. Set all the gain controls on all power amplifiers to known, repeatable settings. The 

preferred setting for most amplifier gain controls is the maximum. If a different 

setting is required in order to optimize the noise performance of the system, the 

controls should be locked in position or marked clearly. 

Caution: The following process causes the CP750 to output pink noise to the power 

amplifiers. 

The CP750 output levels may be set too high. If you are unsure of the settings on 

your unit, turn off the power amplifiers before calibrating SPL. Then, select and 

observe the present output level adjustment settings. 

2. Set up your crossovers if present. 

3. Apply power to the CP750. 

4. Launch the CP750 Setup Software, connect to the unit, and click Alignment. 

The software displays a warning that entering alignment mode will disturb 

auditorium audio. 

5. Click Continue in the warning tab that appears to begin the auditorium alignment 

process. 

The Room Levels tab appears active. 

Room Levels shows a summary of current settings, allows you to calibrate the internal SPL 

meter, allows you to choose a channel with which to work, or to adjust any channel’s level 

with a slider. Each increment of the displayed relative number from a value of 1 to 127, 

represents an increment of approximately 0.25 dB of range adjustment. 

Figure 5‐2 shows an example of the tab before the SPL is calibrated. 



Figure 5‐2 

Figure 5-2 

Alignment Tab Showing Room Levels 

5.4 Calibrating the Internal SPL Meter 

You must calibrate the CP750’s internal SPL before proceeding with alignment. 

1. To start the process, click C under Signal Generator Enable to activate the Center 

channel. 

2. Select Pink Noise from the Signal Mode drop‐down list. Pink noise is sent to the 

Center channel speaker. 

Note: 

The CP750 is shipped from the factory with the Mic. Input level 

control set to the minimum. 

3. Check the microphone level to be sure it appears in the target range as shown in 

Figure 5‐2. 

If necessary, adjust the Mic. Gain on the rear panel of the CP750 until the level is within 

the target range. 


Initial Output-Level Adjustment 

4. With a sound pressure level meter, measure the noise level in the room. Hold the 

sound pressure level meter near the location of mic 1, discussed in Section 5.2. 

5. Enter the measured value into the Measured Value field. 

6. Wait while the system automatically calibrates to the room reading. 

The calibration is retained in CP750 memory and can be used in future alignments. 

However, it is advisable to recalibrate the system when rearranging microphones because 

the sound pressure level varies slightly with microphone placement. 

5.5 Initial Output-Level Adjustment 

Next, adjust each channel slider to make sure the pink noise is audible and to achieve a 

reasonable sound pressure level in the auditorium. It is not necessary to set exact levels 

because the levels will change slightly during equalization. Exact output level adjustment 

is performed after equalization. 

Note: 

For this and all other adjustments using sliders, use the slider to get close to the 

optimal value. Use the up and down arrow keys to make fine adjustments. 

5.5.1 Setting Main Channel Levels 

When the CP750 is first installed, you must repeat these steps for each channel. Values are 

adjusted on the Channel Tune tab after a channel is chosen. Figure 5‐3 shows an example 

with the Center channel selected. 

1. Click a channel radio button to make it active and lock pink noise to it. 

2. Check the level indicated underneath the Channel Level slider, and move it up or 

down until the measured level reads 85 dB. 

3. Repeat steps 1 and 2 for the R and L channels, setting the Channel Level to 85 dB. 

4. Repeat steps 1 and 2 for the Ls, Bsl, R, and Bsr channels, setting each to read 82 dB. 



Figure 5‐3 

Figure 5-3 

Channel Tune Tab Showing the Center Channel 

5.5.2 Subwoofer Levels 

After the last surround channel is adjusted, click LFE to work with it. Pink noise is now 

present on the Subwoofer channel only (140 Hz bandwidth for EQ and level setting 

screens). 

The LFE has distinct options that appear on the Channel Tune tab, as shown in Figure 5‐4. 


Room Equalization 

Figure 5‐4 

Figure 5-4 

Channel Tune Tab Showing LFE EQ 

Initial subwoofer level setting uses a blue reference line displayed on the LFE Channel 

Tune tab, established from the Center channel pink‐noise level. Using the Channel Level 

slider, adjust the level, moving the average subwoofer RTA display to match the reference 

line on the screen as closely as possible. Final subwoofer level adjustments for both digital 

and Dolby ® Pro Logic ® signal paths are carried out later, after the room is equalized. 

5.6 Room Equalization 

Room equalization is performed using the RTA built into the CP750. The desired result is 

a frequency response that closely matches the “x‐curve” overlay (SMPTE 202M‐1998). 

Results achieved within ±3 dB of the x‐curve are considered within tolerance of the 

specification. Small diameter, pressure calibrated microphones are preferred for accuracy 

over large diameter types. Use of a microphone multiplexer will accommodate spatial 



averaging of different positions within the room, which is recommended for best results. 

Follow this sequence: 

1. Perform coarse adjustments of each channel using the Bulk EQ Bass and Treble 

sliders. 

2. Perform fine adjustments of each band using the 27‐band one‐third‐octave equalizer. 

3. Perform LFE channel equalization by setting the frequency, Q (width), and level of 

cut, using the single‐band parametric equalizer. 

5.6.1 Setting Bulk EQ 

This process simultaneously adjusts all bass or all treble frequencies. It is important to 

adjust both of these prior to adjusting the individual one‐third octave bands. 

Bass Level 

The Bass level on the Channel Tune tab is adjustable from –6 to +6 dB in 0.2 dB steps. Using 

the slider, approximate the reference curve as closely as possible. 

Treble Level 

The Treble level is adjustable from –10 to +10 dB in 0.2 dB steps. Using the slider, 

approximate the reference curve as closely as possible. 

Treble Frequency Corner 

The Treble corner frequency can be set to 1, 2, 3, or 4 kHz, and applies to all channels. 

Choose the setting that matches the reference curve most closely. 

5.6.2 Using EQ Assist 

The EQ Assist feature automatically adjusts the frequency response to the x‐curve. Use this 

feature with care since it adjusts adjacent bands as necessary (even to extremes) to achieve 

the exact x‐curve. The EQ Assist feature does not adjust to room anomalies as a human 

operator can, avoiding overcompensation in any frequency bands. 

Note: 

If you use this feature, be sure to use it after adjusting the bass and treble bulk EQ. 

To prevent overcompensation for possible speaker problems, the 20, 25, 30, 40, 50, and 

63 Hz, as well as the 12.5 and16 kHz, bands are not automatically adjusted. You must adjust 

these bands manually. 

5.6.3 Making Fine Adjustments to Individual Bands 

Observe adjacent band effects when adjusting individual frequencies. Be aware of 

frequency bands that are very different from neighboring bands, and use caution so as not 

to overcompensate. (Major differences could be the result of a room node at the particular 

microphone location.) Adjust each frequency band as necessary to achieve a smooth EQ 

with results nearing the x‐curve overlay. The goal is to achieve (or come close to) the 


Final Output-Level Calibration 

x‐curve without overcompensating. Remember that the SMPTE tolerance is ±3 dB, 

although closer results are often easily achieved. 

5.6.4 Adjusting LFE Channel EQ 

Begin with zero cut and observe the worst peak within the spectrum. Adjust the Center 

slider until the frequency matches the peak, and then adjust the Cut to flatten that region. 

Adjust the Q (width) and Cut, until the smoothest response is achieved. 

Equalization facilities for the subwoofer channel are different than for the other channels. 

The process in this manual is designed to correct the principal room resonance in the 

operating range of the subwoofer. The subwoofer equalizer is a cut‐only filter, with 

adjustable center frequency (25 to 125 Hz), Q (center width, selectable among four values), 

and amount of cut (0 to 12 dB). 

After all the full‐range channels have been equalized, follow these steps: 

1. Click LFE to make it the active channel. 

2. Using the slider reduce Cut to 0 dB. This disables EQ so that you can determine the 

low‐frequency resonant peak to be equalized. Note the band where the unequalized 

peak appears. 

3. Using the slider increase Cut to its maximum, 12 dB. 

Using the Center slider moves the dip in the frequency response along the frequency 

axis of the RTA display. 

4. Adjust the center frequency so that the center of the dip is in the same band as the 

peak displayed in the previous unequalized frequency response. 

5. Using the Cut slider, slowly reduce the amount of cut to flatten the dip. The center of 

the dip should be at the same level as the skirts. 

6. Click to check other Q values for the flattest possible frequency response. 

5.7 Final Output-Level Calibration 

Once room equalization is complete, the sound pressure level in the theatre can be set 

accurately. 

5.7.1 Main Channels 

If a microphone multiplexer is being used in your auditorium, move Mic 1 to room center 

two‐thirds back from the screen. 

1. Click the Room Levels tab to activate it. 

2. Using the sliders, set L, C, R to 85 dB, and the surround channels to 82 dB. 

Note: 

Because the sound pressure level calibration was performed earlier, a recalibration 

is not required unless the microphone placement has changed. Repeat the steps in 

Section 5.4 if necessary. 



5.7.2 Subwoofer Channel Level 

Whereas the final sound pressure levels of the main audio channels are ideally adjusted 

with a single microphone two‐thirds back from screen at room center, the subwoofer 

channel level is best adjusted with the microphone multiplexer cycling (if available). 

1. First complete the center channel equalization and level adjustment. 

2. On the Channel Tune tab, click LFE to make it the active channel and select Pink 

Noise as the Signal Mode. 

3. Use the slider and arrow keys to achieve an average level of +10 dB as indicated on the 

spectrum analyzer. 

This is the “digital” level, which is always set 10 dB higher than the center channel. 

4. Click Force PL Cut to activate the Dolby Pro Logic subwoofer and adjust the Cut 

slider to achieve an average level of 0 dB as indicated on the spectrum analyzer. 

The Pro Logic subwoofer is always set to match the level of the center channel and to 

act as bass extension during Pro Logic or Pro Logic II playback. 

5.7.3 Subwoofer Speaker Polarity Check 

To check subwoofer speaker polarity: 

1. Click Center Channel Gen on the Channel Tune tab to generate center‐channel pink 

noise. 

2. Choose a Filter Frequency to select the crossover point between your main speakers 

and the LFE. 

Use 50 Hz if your main speakers are full spectrum. Use 100 Hz otherwise. 

3. Click Phase Invert and watch the behavior of the filter frequency band. There should 

be a level decrease as soon as you click Phase Invert. If you do not see a decrease, the 

polarity of the subwoofer wiring is incorrect. Reverse the subwoofer speaker wire 

connections to correct it. 

The subwoofer polarity always resets to normal after completing this check. Phase 

Invert is a temporary setting for this test only. 

5.8 Final Sound Check 

Follow these steps to do a final equalization check of the auditorium. 

1. On the Room Levels tab, click Rotate under Signal Generator Enable. 

2. Choose Signal Mode Pink Noise to start pink noise. 

Pink noise is sent to each channel in turn, holding for five seconds at each channel. 

Note: 

Unlike the different levels used during alignment, the rotating pink 

noise is set to 85 dB for all channels during this test. Pressing 

stops the pink noise from moving to the next channel. Pressing 

again resumes pink‐noise rotation. 

3. Go to the auditorium and sit two‐thirds of the distance from the front speakers to the 

rear, and at the side‐to‐side center of the room. All channels should sound equally 

loud and have similar frequency response as the noise rotates. An SPL meter can be 

used to confirm accurate and equal level settings. 


Nonsync Level Adjustment 

5.9 Nonsync Level Adjustment 

You can adjust the Nonsync level on the Nonsync Input tab. 

1. Click the Nonsync Input tab to open it. 

2. Play a CD or other audio source on your nonsync device and adjust the slider in the 

setup software for the desired level in the theatre. If possible, select a recording that 

has a natural ambience, such as an orchestral work. 

5.9.1 Noise Floor Optimization 

Noise Floor Optimization calculates and utilizes any available leftover capacity in each 

channel to improve the overall noise floor of the CP750. It operates by measuring the extent 

to which the unit uses the available headroom in the B‐chain, then boosts the overall gain 

to use all available headroom. The analog output level trims are then reduced by the 

amount of that boost, resulting in an optimally reduced noise floor. This adjustment also 

factors in the headroom available to the fader. Changes to the output trim values are 

transparent to the user, and no changes will be seen in the fader values in the setup 

software. Clipping may occur on high level signals if the fader is set above 7.0. 




Chapter 6 

Remote Control and Monitoring 

The CP750 was designed and built to make remote operation and monitoring easy. It 

supports three different remote strategies: 

• Status Monitoring and Level Control in the Setup Software 

• ASCII Control 

• SNMP 

6.1 Status Monitoring and Level Control in the Setup Software 

The virtual status monitor at the bottom of the setup software screens shown in Figure 6‐1 

provides a user‐friendly interface. Its signal‐presence meter monitors the CP750 analog 

output. There is a virtual input selector for each CP750 input. Clicking any of these buttons 

activates the associated input. Each of the digital input virtual buttons has an associated 

virtual LED, indicating a valid signal. The software also echoes the state of the front‐panel 

display and fader. Any action available at the unit front panel can be executed through the 

remote software. 

Figure 6‐1 

Figure 6-1 

Virtual Status Monitor 

6.2 ASCII Control 

Full control of the CP750 is available through a set of ASCII commands and queries. No 

error correction (CRC), sync bytes, or protocol is applied to this interface. 

6.2.1 Connections 

ASCII commands can be communicated over any of three ports: 

• The RS-232 connector supports standard 9‐pin serial connections to PC serial ports 

and other RS‐232 devices. It operates at 9600 baud with 8 data bits, 1 stop bit, no 

parity, and no flow control. It cannot be invoked while the serial data port is in use by 

the CP750 setup program. 



• The Ethernet connector supports direct and switched Telnet connections to port 61408. 

Note: 

Note the port number. Telnet programs default to port 23. You must 

correctly enter 61408 to connect to the CP750. 

The system accepts 20 simultaneous connections on the TCP port concurrent with one 

on each of the other ports. The 21st TCP connection causes the oldest TCP session to 

disconnect, and sends a warning message to the client. 

• The Remote RJ‐45 connector operates at 9600 bps with 8 data bits, 1 stop bit, no parity, 

and no flow control. 

Characters are not echoed back to the controller, and the Ethernet and Remote connections 

do not support terminal control characters such as . The RS-232 connector 

does support terminal control characters and is therefore the most user friendly. 

6.2.2 Standard and Full Control 

Under normal operating conditions, a user needs only a subset of all the available 

commands. But installers and expert users need and want full control of the system. The 

standard command set is available when cp750.ctrl.full_ascii_ctrl is 0. The full 

command set is available when cp750.ctrl.full_ascii_ctrl is 1. 

6.2.3 Command Syntax 

Command parsing is not case sensitive. White space is ignored on input lines. 

Most commands consist of a parameter name followed by a space and a value. 

cp750.sys.input_mode dig_2 instructs the system to use digital input 2. 

The system responds with status text verifying that the value has been set: 

cp750.sys.input_mode dig_2 

Queries consist of a parameter name followed by a space and a question mark. 

cp750.sys.input_mode ? asks which input the system is currently using. 

The system responds with status text for the specified parameter. 

cp750.sys.input_mode dig_2 

If you send an unrecognized value, the system takes no action and returns parameter 

status. If you send an unrecognized parameter, the system returns a blank new line. No 

error messages are generated. 

There is also a small set of single word commands such as help, status, and exit. 


ASCII Control 

6.2.4 Command Sets 

The normal set of commands is listed in Table 6‐1. The commands included in the full set 

are listed in Table 6‐2. 

Table 6-1 

Normal Commands 

Parameter Name Valid Values Description and Comments 

cp750.sysinfo.version 1.0.0.150183 

cp750.ctrl.default_params 0, 1 

cp750.ctrl.fader_delta –100 to 100 

cp750.ctrl.full_ascii_ctrl 0, 1 

cp750.ctrl.log_erase 0, 1 

cp750.ctrl.reboot 0 to 2147483647 

cp750.sys.analog_global_delay 0 to 250 

cp750.sys.analog_route [L R C Sw Ls Rs 7 8] 

cp750.sys.dig_1_global_delay 0 to 250 

cp750.sys.dig_1_route [L R C Sw Ls Rs 7 8] 




p750.sys.dolby_digital_2_channel_decode_ 

mode_1 

cp750.sys.dolby_digital_2_channel_decode 

_mode_2 


_mode_3 


_mode_4 

cp750.sys.dolby_digital_dialnorm_1 



auto | invalid | lr_discrete | 

n_a | prologic | prologic_2 







n_a | off | on 



cp750.sys.dolby_digital_dialnorm_4 n_a | off | on 

cp750.sys.fader 0 to 100 

cp750.sys.fader_preset_1 0 to 100 

cp750.sys.fader_preset_1_enable 0, 1 







cp750.sys.fader_preset_a 0 to 100 

cp750.sys.fader_preset_a_enable 0, 1 

cp750.sys.fader_preset_m 0 to 100 

cp750.sys.fader_preset_m_enable 0, 1 

cp750.sys.fader_preset_n 0 to 100 

cp750.sys.fader_preset_n_enable 0, 1 

cp750.sys.input_mode 

analog | dig_1 | dig_2 | dig_3 

| dig_4 | last | mic | non_sync 

cp750.sys.ip_setting 

[ip.ip.ip.ip nm.nm.nm.nm 

gw.gw.gw.gw off|on 

hostname] 

cp750.sys.mic_global_delay 0 to 250 



Table 6-1 

Normal Commands (Continued) 


cp750.sys.non_sync_global_delay 0 to 250 

cp750.sys.non_sync_route [L R] 

cp750.sys.ntp_server 

[hostname | ip_address] 

cp750.sys.pcm_2_channel_decode_mode_1 auto | invalid | lr_discrete | 








cp750.sys.pcm_2_channel_decode_mode_a auto | invalid | lr_discrete | 


cp750.sys.pcm_2_channel_decode_mode_n auto | invalid | lr_discrete | 


cp750.sys.power_on_input 



cp750.sys.process_mode_1 minimum_latency | mute | 

silent_switch 


silent_switch 


silent_switch 


silent_switch 

cp750.sys.subwoofer_filter 50 to 100 

cp750.sys.surround_delay 0 to 150 

cp750.sys.time 

cp750.sys.time_update_int 1 to 60 

cp750.sys_tune.dsp_1 








dump_log_100 

Prints 100 most recent log events 

dump_log 

Prints entire log 

help 

status 

cp750.. ? 

Basic query format 

exit 

Table 6-2 

Full Control Commands 


cp750.sysinfo.version 1.0.0.150183 

cp750.ctrl.alignment_mode_tickle 0 to 2147483647 

cp750.ctrl.default_params 0, 1 


ASCII Control 

Table 6-2 

Full Control Commands (Continued) 


cp750.ctrl.fader_delta –100 to 100 

cp750.ctrl.full_ascii_ctrl 0, 1 

cp750.ctrl.log_erase 0, 1 

cp750.ctrl.reboot 0 to 2147483647 

cp750.internal.save_params 0, 1 

cp750.internal.tecs_set_test_mode 0, 1 

cp750.state.bitstream_format Dolby_Digital | PCM | n_a 

cp750.state.channel_mode 1_0 | 1_1 | 2_0 | 2_1 | 2_2 | 3_0 

| 3_1 | 3_2 | 3_2_L | n_a 

cp750.state.data_rate 112 | 128 | 160 | 192 | 224 | 256 

| 32 | 320 | 384 | 40 | 448 | 48 | 

512 | 56 | 576 | 64 | 640 | 80 | 

96 | n_a 

cp750.state.decode_mode auto | invalid | lr_discrete | 


cp750.state.dialnorm –31 to 0 

cp750.state.dig_1_valid 0, 1 




cp750.state.headless 0, 1 

cp750.state.ip_status 

cp750.state.meters 

cp750.state.rta 

cp750.state.rta_avg 0 to 255 

cp750.state.sample_rate 

32 | 44_1 | 48 | 88_2 | 96 | n_a 

cp750.state.spl –5000 to 5000 

cp750.state.spl_calibrated 0, 1 

cp750.state.spl_stable 0, 1 

cp750.state.time 

cp750.sys.alignment_mode 


cp750.sys.analog_global_delay 0 to 250 

cp750.sys.analog_route [ L R C Sw Ls Rs 7 8 ] 

cp750.sys.analog_text 

cp750.sys.auditorium_number 

cp750.sys.automation_text 

cp750.sys.bass_level_bsl –60 to 60 

cp750.sys.bass_level_bsr –60 to 60 

cp750.sys.bass_level_c –60 to 60 

cp750.sys.bass_level_l –60 to 60 

cp750.sys.bass_level_ls –60 to 60 

cp750.sys.bass_level_r –60 to 60 

cp750.sys.bass_level_rs –60 to 60 

cp750.sys.cinema_system_text 

cp750.sys.comment_text 

cp750.sys.cp_text 


cp750.sys.dig_1_route [ L R C Sw Ls Rs 7 8 ] 

cp750.sys.dig_1_text 




Table 6-2 








cp750.sys.distance_units 

feet | meters 

cp750.sys.dolby_digital_2_channel_d 

ecode_mode_1 


ecode_mode_2 


ecode_mode_3 


ecode_mode_4 

















cp750.sys.eq_bsl_100 –60 to 60 

cp750.sys.eq_bsl_10k –60 to 60 

cp750.sys.eq_bsl_125 –60 to 60 

cp750.sys.eq_bsl_12_5k –60 to 60 

cp750.sys.eq_bsl_160 –60 to 60 





cp750.sys.eq_bsl_200 –60 to 60 

cp750.sys.eq_bsl_250 –60 to 60 



cp750.sys.eq_bsl_315 –60 to 60 


cp750.sys.eq_bsl_40 –60 to 60 

cp750.sys.eq_bsl_400 –60 to 60 



cp750.sys.eq_bsl_500 –60 to 60 



cp750.sys.eq_bsl_630 –60 to 60 



cp750.sys.eq_bsl_800 –60 to 60 


cp750.sys.eq_bsr_100 –60 to 60 

cp750.sys.eq_bsr_10k –60 to 60 

cp750.sys.eq_bsr_125 –60 to 60 

cp750.sys.eq_bsr_12_5k –60 to 60 

cp750.sys.eq_bsr_160 –60 to 60 


ASCII Control 

Table 6-2 







cp750.sys.eq_bsr_200 –60 to 60 

cp750.sys.eq_bsr_250 –60 to 60 



cp750.sys.eq_bsr_315 –60 to 60 


cp750.sys.eq_bsr_40 –60 to 60 

cp750.sys.eq_bsr_400 –60 to 60 



cp750.sys.eq_bsr_500 –60 to 60 



cp750.sys.eq_bsr_630 –60 to 60 



cp750.sys.eq_bsr_800 –60 to 60 


cp750.sys.eq_c_100 –60 to 60 

cp750.sys.eq_c_10k –60 to 60 

cp750.sys.eq_c_125 –60 to 60 

cp750.sys.eq_c_12_5k –60 to 60 

cp750.sys.eq_c_160 –60 to 60 

cp750.sys.eq_c_16k –60 to 60 

cp750.sys.eq_c_1_25k –60 to 60 

cp750.sys.eq_c_1_6k –60 to 60 

cp750.sys.eq_c_1k –60 to 60 

cp750.sys.eq_c_200 –60 to 60 

cp750.sys.eq_c_250 –60 to 60 

cp750.sys.eq_c_2_5k –60 to 60 

cp750.sys.eq_c_2k –60 to 60 

cp750.sys.eq_c_315 –60 to 60 

cp750.sys.eq_c_3_15k –60 to 60 

cp750.sys.eq_c_40 –60 to 60 

cp750.sys.eq_c_400 –60 to 60 

cp750.sys.eq_c_4k –60 to 60 

cp750.sys.eq_c_50 –60 to 60 

cp750.sys.eq_c_500 –60 to 60 

cp750.sys.eq_c_5k –60 to 60 

cp750.sys.eq_c_63 –60 to 60 

cp750.sys.eq_c_630 –60 to 60 

cp750.sys.eq_c_6_3k –60 to 60 

cp750.sys.eq_c_80 –60 to 60 

cp750.sys.eq_c_800 –60 to 60 

cp750.sys.eq_c_8k –60 to 60 



Table 6-2 



cp750.sys.eq_l_100 –60 to 60 

cp750.sys.eq_l_10k –60 to 60 

cp750.sys.eq_l_125 –60 to 60 

cp750.sys.eq_l_12_5k –60 to 60 

cp750.sys.eq_l_160 –60 to 60 

cp750.sys.eq_l_16k –60 to 60 

cp750.sys.eq_l_1_25k –60 to 60 

cp750.sys.eq_l_1_6k –60 to 60 

cp750.sys.eq_l_1k –60 to 60 

cp750.sys.eq_l_200 –60 to 60 

cp750.sys.eq_l_250 –60 to 60 

cp750.sys.eq_l_2_5k –60 to 60 

cp750.sys.eq_l_2k –60 to 60 

cp750.sys.eq_l_315 –60 to 60 

cp750.sys.eq_l_3_15k –60 to 60 

cp750.sys.eq_l_40 –60 to 60 

cp750.sys.eq_l_400 –60 to 60 

cp750.sys.eq_l_4k –60 to 60 

cp750.sys.eq_l_50 –60 to 60 

cp750.sys.eq_l_500 –60 to 60 

cp750.sys.eq_l_5k –60 to 60 

cp750.sys.eq_l_63 –60 to 60 

cp750.sys.eq_l_630 –60 to 60 

cp750.sys.eq_l_6_3k – 60 to 60 

cp750.sys.eq_l_80 –60 to 60 

cp750.sys.eq_l_800 –60 to 60 

cp750.sys.eq_l_8k –60 to 60 

cp750.sys.eq_lfe_cut –126 to 0 

cp750.sys.eq_lfe_freq 25 to 125 

cp750.sys.eq_lfe_q 0_5 | 1_0 | 2_0 | 4_0 

cp750.sys.eq_ls_100 –60 to 60 

cp750.sys.eq_ls_10k –60 to 60 

cp750.sys.eq_ls_125 –60 to 60 

cp750.sys.eq_ls_12_5k –60 to 60 

cp750.sys.eq_ls_160 –60 to 60 


cp750.sys.eq_ls_1_25k –60 to 60 

cp750.sys.eq_ls_1_6k –60 to 60 


cp750.sys.eq_ls_200 –60 to 60 

cp750.sys.eq_ls_250 –60 to 60 

cp750.sys.eq_ls_2_5k –60 to 60 


cp750.sys.eq_ls_315 –60 to 60 

cp750.sys.eq_ls_3_15k –60 to 60 

cp750.sys.eq_ls_40 –60 to 60 

cp750.sys.eq_ls_400 –60 to 60 


cp750.sys.eq_ls_50 –60 to 60 


ASCII Control 

Table 6-2 



cp750.sys.eq_ls_500 –60 to 60 


cp750.sys.eq_ls_63 –60 to 60 

cp750.sys.eq_ls_630 –60 to 60 

cp750.sys.eq_ls_6_3k –60 to 60 

cp750.sys.eq_ls_80 –60 to 60 

cp750.sys.eq_ls_800 –60 to 60 


cp750.sys.eq_r_100 –60 to 60 

cp750.sys.eq_r_10k –60 to 60 

cp750.sys.eq_r_125 –60 to 60 

cp750.sys.eq_r_12_5k –60 to 60 

cp750.sys.eq_r_160 –60 to 60 

cp750.sys.eq_r_16k –60 to 60 

cp750.sys.eq_r_1_25k –60 to 60 

cp750.sys.eq_r_1_6k –60 to 60 

cp750.sys.eq_r_1k –60 to 60 

cp750.sys.eq_r_200 –60 to 60 

cp750.sys.eq_r_250 –60 to 60 

cp750.sys.eq_r_2_5k –60 to 60 

cp750.sys.eq_r_2k –60 to 60 

cp750.sys.eq_r_315 –60 to 60 

cp750.sys.eq_r_3_15k –60 to 60 

cp750.sys.eq_r_40 –60 to 60 

cp750.sys.eq_r_400 –60 to 60 

cp750.sys.eq_r_4k –60 to 60 

cp750.sys.eq_r_50 –60 to 60 

cp750.sys.eq_r_500 –60 to 60 

cp750.sys.eq_r_5k –60 to 60 

cp750.sys.eq_r_63 –60 to 60 

cp750.sys.eq_r_630 –60 to 60 

cp750.sys.eq_r_6_3k –60 to 60 

cp750.sys.eq_r_80 –60 to 60 

cp750.sys.eq_r_800 –60 to 60 

cp750.sys.eq_r_8k –60 to 60 

cp750.sys.eq_rs_100 –60 to 60 

cp750.sys.eq_rs_10k –60 to 60 

cp750.sys.eq_rs_125 –60 to 60 

cp750.sys.eq_rs_12_5k –60 to 60 

cp750.sys.eq_rs_160 –60 to 60 


cp750.sys.eq_rs_1_25k –60 to 60 

cp750.sys.eq_rs_1_6k –60 to 60 


cp750.sys.eq_rs_200 –60 to 60 

cp750.sys.eq_rs_250 –60 to 60 

cp750.sys.eq_rs_2_5k –60 to 60 


cp750.sys.eq_rs_315 –60 to 60 



Table 6-2 



cp750.sys.eq_rs_3_15k –60 to 60 

cp750.sys.eq_rs_40 –60 to 60 

cp750.sys.eq_rs_400 –60 to 60 

p750.sys.eq_rs_4k –60 to 60 

cp750.sys.eq_rs_50 –60 to 60 

cp750.sys.eq_rs_500 –60 to 60 


cp750.sys.eq_rs_63 –60 to 60 

cp750.sys.eq_rs_630 –60 to 60 

cp750.sys.eq_rs_6_3k –60 to 60 

cp750.sys.eq_rs_80 –60 to 60 

cp750.sys.eq_rs_800 –60 to 60 


cp750.sys.fader 0 to 100 









cp750.sys.fader_preset_a 0 to 100 

cp750.sys.fader_preset_a_enable 0, 1 

cp750.sys.fader_preset_m 0 to 100 

cp750.sys.fader_preset_m_enable 0, 1 

cp750.sys.fader_preset_n 0 to 100 

cp750.sys.fader_preset_n_enable 0, 1 

cp750.sys.input_mode 



cp750.sys.ip_setting 

[ ip.ip.ip.ip nm.nm.nm.nm 

gw.gw.gw.gw off|on hostname 

] 

cp750.sys.lcd_contrast 0 to 31 

cp750.sys.level_bsl –160 to 160 

cp750.sys.level_bsr –160 to 160 

cp750.sys.level_c –160 to 160 

cp750.sys.level_l –160 to 160 

cp750.sys.level_lfe –160 to 160 

cp750.sys.level_ls –160 to 160 

cp750.sys.level_r –160 to 160 

cp750.sys.level_rs –160 to 160 

cp750.sys.mic_global_delay 0 to 250 

cp750.sys.mic_text 

cp750.sys.mute 0, 1 

cp750.sys.mute_fade_in_time 200 to 5000 

cp750.sys.mute_fade_out_time 200 to 5000 

cp750.sys.non_sync_global_delay 0 to 250 

cp750.sys.non_sync_route [ L R] 

cp750.sys.non_sync_text 


ASCII Control 

Table 6-2 



cp750.sys.ntp_server 

[ hostname | ip_address] 

cp750.sys.pcm_2_channel_decode_m 

ode_1 




ode_2 


n_a | prologic |prologic_2 


ode_3 




ode_4 




ode_a 




ode_n 



cp750.sys.power_on_input 




silent_switch 


silent_switch 


silent_switch 


silent_switch 

cp750.sys.projector_text 

cp750.sys.rta_channel 

Bsl | Bsr | C | L | LFE | Ls | R 

| Rs 

cp750.sys.screen_distance 0 to 2147483647 

cp750.sys.serial_number 0 to 2147483647 

cp750.sys.signal_gen_channel Bsl | Bsr | C | L | LFE | Ls | R 

| Rs 

cp750.sys.signal_gen_mode off | pink | program | sine_100 

| sine_10k | sine_1k | thump 

cp750.sys.speaker_distance 0 to 2147483647 

cp750.sys.spl_room –5000 to 5000 

cp750.sys.subwoofer_filter: 50 to 100 

cp750.sys.surround_delay 0 to 150 

cp750.sys.theater_name 

cp750.sys.time 

cp750.sys.time_update_int 1 to 60 

cp750.sys.treble_freq_bsl 1 to 4 

cp750.sys.treble_freq_bsr 1 to 4 

cp750.sys.treble_freq_c 1 to 4 

cp750.sys.treble_freq_l 1 to 4 

cp750.sys.treble_freq_ls 1 to 4 

cp750.sys.treble_freq_r 1 to 4 

cp750.sys.treble_freq_rs 1 to 4 

cp750.sys.treble_level_bsl –120 to 120 

cp750.sys.treble_level_bsr –120 to 120 

cp750.sys.treble_level_c –120 to 120 

cp750.sys.treble_level_l –120 to 120 

cp750.sys.treble_level_ls –120 to 120 



Table 6-2 



cp750.sys.treble_level_r –120 to 120 

cp750.sys.treble_level_rs –120 to 120 

cp750.sys.velocity_helper 0, 1 







cp750.sys_tune.dsp_7 : 


cp750.sys_tune.dsp_boot_delay_us 0 to 2147483647 

cp750.sys_tune.dsp_fade_time_ms 0 to 2147483647 

cp750.sys_tune.log_interval 1 to 60000 

cp750.sys_tune.meter_rate 0 to 30 

cp750.sys_tune.rta_rate 0 to 30 

cp750.sys_tune.upgrade_timeout 120 to 1800 

cp750.sys_tune.usb_cycle_time: 1 to 

30 

cp750.sysinfo.ethernet_address 

cp750.sysinfo.hardware_rev 0 to 16 

cp750.sysinfo.parameter_file_version 

dump_log_100 

Prints most recent 100 log events 

dump_log 

Prints entire log 

help 

Lists commands and valid values 

status 

Lists current unit state 

cp750.. ? 

Basic query format 

exit 

6.3 SNMP 

The CP750 runs an SNMP agent that communicates over the Ethernet connector in the rear 

panel. 

The CP750 supports a wide variety of standard MIBs listed in Table 6‐3, Table 6‐4, and 

Table 6‐5. In cases where the CP750 does not support the entire MIB, the supported sections 

are indicated by title in the tables. 

Table 6-3 

Supported MIB-2 MIBS 

RFC 

Supported Sections 

RFC 1213 (3418?) System group 

RFC 4293 

IP‐MIB scalars, ipAddressPrefix table, ipAddressTable, ipNetToPhysical 

table, ipNetToMedia table, ipSystemStatsTable, ipIfStatsTable, 

ipDefaultRouterTable, ipv4InterfaceTable, ipv6InterfaceTable, 

ipv6ScopeZoneIndexTable, ipv6RouterAdvertTable, icmpStatsTable, 

icmpMsgStatsTable 

RFC 2683 

IF‐MIB scalars, ifTable, ifXTable 

RFC 4022 TCP‐MIB scalars, tcpConnection table, tcpListener table 

RFC 4113 UDP‐MIB scalars, udpEndpoint table 


SNMP 

Table 6-4 

Other Standard MIBs 

RFC 

Supported Sections 

RFC2006 MIP‐MIB, faRegistration group 

RFC 4292 IP‐FORWARD‐MIB ipForward, inetCidrRoutNumber, 

inetCidrRouteDiscards, inetCidrRoute table 

Table 6-5 

V3 MIBS 

RFC 3411 

RFC 3412 

RFC 3413 

RFC 3414 

RFC 2786 

RFC 3415 

RFC 3417 

RFC 3584 

SNMP‐FRAMEWORK MIB 

SNMP‐MPD‐MIB 

SNMP‐TARGET‐MIB, SNMP‐NOTIFICATION‐MIB, SNMP‐PROXY‐MIB 

USM‐MIB 

USM‐DH‐OBJECTS‐MIB 

VACM‐MIB 

SNMPv2‐TM mib 

SNMP‐COMMUNITY‐MIB 

In addition, the CP750 supports local SNMP variables, listed in the DOLBY‐CP750‐MIB. 

All Dolby ® MIBs are available on the Dolby Digital Cinema Resources CD, and from sales 

representatives and technicians. 




Chapter 7 

Technical Reference 

7.1 CP750 Specifications 

7.1.1 Audio Inputs 

Digital Input 1 

4xAES, 25‐pin female D‐connector provides four AES/EBU channel pair inputs 

Input impedance: 110 balanced. The four AES input signals must be time aligned with 

each other. 

Digital Input 2, Digital Input 3 

1xAES, male BNC connector, unbalanced but floating, per AES‐3id‐1995/SMPTE 276M 

Input impedance: 75 

Digital Input 4 

Optical Toslink connector for digital input 

Multichannel Analog Input 

Eight‐channel, balanced analog, 10 kdifferential input impedance, 300 mV reference 

level 25‐pin female D‐connector 

NonSync Input 

Two‐channel, RCA connector, 21 k input impedance, adjustable input level 

Microphone Input 

XLR connector, standard pinout, 10 kdifferential input impedance, 12 V phantom power 

available, adjustable gain 

7.1.2 Audio Outputs 

Main Audio Output 

Eight‐channel, balanced analog, 100 differential output impedance, 25‐pin male 

D‐connector 

Do not load with less than 600 differential. 



Aux Output 

Two‐channel, unbalanced analog, 200 mV reference level, 100 output impedance, RCA 

connectors, always routes channel pair 7/8 of 4xAES input for alternate uses such as H/I & 

VI‐N transmitters. 

Note: 

This fixed level output has no EQ and is not controlled by either the fader or mute 

controls. 

H/I Output 

1 channel, unbalanced analog, 70 mV fixed reference level, 100 output impedance, RCA 

connector, center‐weighted sum of Left, Center, Right 

7.1.3 Other Input/Output 

Ethernet Port 

RJ‐45 for network connection and PC setup software 

Automation Port 

25‐pin female D‐connector, floating ground 

RS-232 Port 

9‐pin female D‐connector 

Remote Port 

RJ‐45 connector for optional Cat. No. 868 Remote Fader (not an Ethernet connection) 

Backup Power Connector 

For optional Cat. No. 994 External Power Supply 

AC Mains Input 

Unswitched IEC power inlet module 

USB Port 

For connection to PC to run setup software 


CP750 Specifications 

7.1.4 Audio Processing 

PCM 

32, 44.1, 48, and 96kHz; 16‐, 20‐, 24‐bit 

Dolby Digital (AC-3) 

Up to 5.1 channels 

Dolby Pro Logic 

Left, Center, Right, Surround (Subwoofer optional) 

Dolby Pro Logic II 

Left, Center, Right, Left surround, Right surround (Subwoofer optional) 

Dolby Surround EX 

Left, Center, Right, Left surround, Back surround, Right surround, Subwoofer 

Nonsync 

Left, Right, Surround (Subwoofer optional) 

7.1.5 Other Parameters 

Global Audio Delay 

Adjustable delay of all channels from 0–250 ms; each input may be adjusted separately 

Surround Delay 

Digital Surround delay, 0–150 ms 

Dolby ® Pro Logic ® Surround delay, 20–150 ms 

Equalization 

Eight‐channel one‐third‐octave plus parametric for Subwoofer channel 

Dynamic Range 

105 dB clip to CCIR/AMR weighted typical without noise optimizer enabled 

Distortion 


7.1.6 Optional Accessories Ordered Separately 

Cat. No. 994 Backup Power Supply 

Cat. No. 868 Remote Fader 

CP750‐CK Connector Kit 

7.1.7 Power Requirements 

100–240 VAC, 50–60 Hz 

7.1.8 Construction 

2‐U rackmount chassis frame 

7.1.9 Dimensions and Weight 

Width 17 in (432 mm) 

Height 3.5 in (89 mm) 

Overall depth, including connectors and fader knob: 10.6 in (269 mm) 

Depth behind rack ears, including connectors: 9.75 in (248 mm) 

Weight: 9.4 lb (4.2 kg) 

7.1.10 PC Connection 

USB port for setup operations and software upgrades 

7.1.11 Input Selector Buttons 

Four digital input source buttons 

Eight‐channel analog input 

Nonsync input 

Mic input 

7.1.12 Indicators 

Valid LEDs indicate digital input clock presence for each digital input 

LCD front‐panel indicates PCM or Dolby Digital processing 

Pro Logic II, Pro Logic, or Discrete decode modes indicated by LCD text 

7.1.13 Environmental Conditions 

Operating: 0°C to 40°C (32°F to 104°F) 

Nonoperating (storage): 0°C to 85°C (32°F to 185°F) 

Humidity: 20 to 80 percent relative, noncondensing 


Rear-Panel Connector Descriptions and Types 

7.1.14 Regulatory Notices 

North America: This unit complies with the limits for a Class A digital device, pursuant to 

Part 15 of the FCC rules, and Industry Canada ICES‐003 specifications. It is UL Listed for 

both US and Canada. 

Europe: This unit complies with the requirements of Low Voltage Directive 2006/95/EC and 

EMC Directive 2004/108/EC and carries the CE marking accordingly. 

Warranty 

One‐year limited, parts and labor. Specifications subject to change without notice. 

7.2 Rear-Panel Connector Descriptions and Types 

All connectors with non‐standard pinouts are described in this section. 

Table 7-1 


Panel Label Description Type 

BACKUP POWER 

4‐pin XLR for connecting the Cat. No. 994 back up 

power supply 

XLR F 

RS-232 For ASCII command string automation control DB‐9 F 

Ethernet For connection to the auditorium network RJ‐45 

REMOTE For connection to Cat. No. 868 Remote Fader RJ‐45 

4xAES IN 4 x AES/EBU input (eight‐channel PCM audio) DB‐25 F 

AUTOMATION For theatre automation control input (momentary DB‐25 F 

contact) 

MAIN AUDIO OUTPUT Eight‐channel balanced floating analog output: DB‐25 M 

L, C, R, Ls, Rs, Sw, 7, 8 

MIC. INPUT 3‐pin, female XLR connector XLR F 

MULTI-CHANNEL Eight‐channel balanced floating analog input for DB‐25 F 

ANALOG INPUT external processor, such as a Dolby DA20 

7.2.1 Backup Power Connector 

Figure 7‐1 

Figure 7-2 

Figure 7-1 

Backup Power Connector Detail 



Figure 7‐3 

Table 7-2 

Backup Power Connector Pinout 

XLR Pin 

1 +15 V input 

2 +5 V input 

3 Ground 

4 –15 V input 

5 (Shell) Ground 

Connection 

7.2.2 RS-232 Serial Port 

9600 baud, no parity, 1 stop bit 

Table 7-3 

Serial Port Pinout 

Pin 

Connection 

1 No connection 

2 Data out (TXD) 

3 Data in (RXD) 

4 Connected to pin 6 

5 Chassis ground 





7.2.3 Remote Fader Connector 

Figure 7‐4 

Figure 7-2 

Table 7-4 

Cat. No. 868 Remote Fader Connector Detail 

Remote Fader Connector Pinout 

RJ-45 Pin 

Fader Connection 

1 TX+ 

2 TX– 

3 RX+ 

4 +15 V 


6 RX– 

7 Ground 




7.2.4 4xAES IN Connector 

This is a female 25‐pin D‐connector. 

Table 7-5 

4xAES IN Connector Pinout 

25-Pin 

D-Connector 

Connection 

1 AES common 

2 CH1/2 – 

3 CH3/4 + 

4 AES common 

5 CH5/6 – 

6 CH7/8 + 

7 AES common 


9 AES common 



12 AES common 


14 CH1/2 + 

15 AES common 

16 CH3/4 – 

17 CH5/6 + 

18 AES common 

19 CH7/8 – 

20 AES common 



23 AES common 





7.2.5 Automation Connector 

This is a female 25‐pin D‐connector. 

To assert a CTRLx pin, connect it to pin 12. 

All output voltages and current are respect to pin 12. 

Table 7-6 

Automation Connector Pinout 

DB-25 Pin Connection Description 

1 CTRL0 – Automation Read Digital 1 button 




5 CTRL4 – Automation Read Multichannel Analog button 

6 CTRL5 – Automation Read Nonsync button 

7 CTRL6 – Automation Read Microphone button 

8 CTRL7 – Automation Read Unused 


10 Mute command Input 


12 Return (for all Automation functions as 

well as Automaton Power) 

13 Automation Power Output (+5v at a Input 

maximum of 50 mA.) 

14 ID0 – Tally Output Digital 1 LED 




18 ID4 – Tally Output Multichannel Analog LED 

19 ID5 – Tally Output Nonsync LED 

20 ID6 – Tally Output Microphone LED 

21 ID7 – Tally Output Unused 


23 Mute indicator (Low = muted) Output 



7.2.6 Mic. Input Connector 

This is a 3‐pin female XLR connector. 

Figure 7‐5 

Figure 7-3 

Mic. Input Connector Detail 



lMain Audio Ouput and Multi‐Channel Audio Input Connectors 

Table 7-7 

Mic. Input Connector Pinout 

XLR Pin 

1 Shield 

2 + Signal 

3 – Signal 

Signal 

7.2.7 Main Audio Output and Multi-Channel Input Connectors 

The pinout is the same for both these connectors, as shown in Table 7‐8. The MAIN AUDIO 

OUTPUT connector is male, pin 1 is at the upper left. The MULTI-CHANNEL AUDIO INPUT 

connector is female, pin 1 is at the upper right. 

Table 7-8 

Main Audio Output and Multi-Channel Audio Input Connector Pinout 

DB-25 Pin Signal Name 

1 Chassis 

2 L+ 

3 Le– 

4 Chassis 

5 C+ 

6 Re– 

7 Chassis 

8 R+ 

9 Chassis 

10 Ls– 

11 Rs– 

12 SW– 

13 Chassis 

14 L– 

15 Chassis 

16 Le+ 

17 C– 

18 Chassis 

19 Re+ 

20 R– 

21 Chassis 

22 Chassis 

23 Ls+ 

24 Rs+ 

25 SW+ 



7.2.8 RS-232 ASCII String Commands 

Table 7-9 

ASCII String Commands 

CP750 ASCII String 

CP750.sys.dig_1_global_delay 0–250 

Parameter or Action 




CP750.sys.dolby_digital_2_channel_decode_m auto | lr_discrete | prologic | prologic_2 

ode 

CP750.sys.dolby_digital_dialnorm 

off | on 

CP750.sys.dolby_e_2_channel_decode_mode auto | lr_discrete | prologic | prologic_2 

CP750.sys.dolby_e_dialnorm 

off | on 

CP750.sys.dolby_e_program 1–4 

CP750.sys.input_mode 

dig_1 | dig_2 | dig_3 | dig_4 | film 

CP750.sys.ip_setting 

[ ip.ip.ip.ip nm.nm.nm.nm gw.gw.gw.gw 

off|on hostname ] 

CP750.sys.ntp_server [ hostname | ip_address ] 

CP750.sys.pcm_2_channel_decode_mode lr_discrete | prologic | prologic_2 

CP750.sys.pcm_mute 

off | on 

CP750.sys.pcm_route_1 

C | L | LFE | Le | Ls | R | Re | Rs 















CP750.sys.power_on_input 

dig_1 | dig_2 | dig_3 | dig_4 | film | last 

CP750.sys.silent_switch 

off | on 

CP750.sys.subwoofer_filter 50–100 

CP750.sys.surround_delay 0–150 

help 

Returns list of commands 

status 

Returns all parameter status 

mfg_print_log 

extract event log 

Legacy ASCII Strings 

Parameter or Action 

4xaes_input 

dig_1 input mode (DMA8 legacy string) 

aes_input 


optical_input 


film 

film input mode (DMA8 legacy string) 

7.3 Remote Commands and Control 

The CP750 is designed for remote communication using serial or Ethernet connections. 

7.3.1 Serial 

ASCII character strings sent to the rear‐panel serial port can be used to set CP750 

parameters and obtain current CP750 status information. The currently available remote 

commands are listed in Table 7‐9. 


Remote Commands and Control 

Serial Communication 

Connections can be made from the CP750 rear‐panel serial port to a PC serial port or other 

RS‐232 device. The serial port speed on your PC should be set to 9600 baud, 8 data bits, no 

parity, 1 stop bit. After the CP750 is powered on, the commands can simply be typed from 

a program such as HyperTerminal. 

7.3.2 Ethernet 

ASCII character strings can be sent through telnet to set CP750 parameters and obtain 

current CP750 status information. The currently available remote commands are listed in 

Table 7‐9. 

Ethernet Communication 

Default CP750 Ethernet Parameters 

IP Address: 192.168.1.136 

Subnet Mask (Netmask): 255.255.255.128 

Gateway: 192.168.1.129 

ASCII control over TCP command strings must be sent to port 61408. 

DHCP is off.

Dolby CP750 Digital Cinema Processor Manual - Projectionniste.net

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